The Alchemist couldn't stop smiling the next morning as she helped the Doctor power up the TARDIS, ready to head off on their first adventure. The TARDIS seemed to be responding to every single move she made, handling so much easier than she had been before. "I told you she loves you," the Doctor grinned.

"And now I can really tell," the Alchemist smiled, patting the time rotor, grinning widely when the TARDIS hummed, her lights brightening. "It's just . . . " She shook her head, tilting her head at him. "That wasn't all a dream, was it?"

"I certainly hope not," the Doctor scoffed, stepping to her side and brushing her hair behind her ear. "And if it is . . . " He kissed her, and she responded, both of them . . . quite breathless when they were done. "I definitely do not want to wake up," he finished.

She grinned. "Me neither."

The Doctor grinned back and finished powering up the TARDIS, and the Alchemist poked her head out of the door. "Rose!" she called, the girl finishing up saying goodbye to her mum and Mickey. "Let's move it!"

"Shut up!" Rose laughed, making the Alchemist wink. She turned to Jackie. "I'm going now," she smiled. "I love you!"

"I love you," Jackie smiled, giving her a hug.

Rose hugged her back, turning to Mickey. "Love you, love you," she said, giving him a kiss.

"Love you," Mickey replied.

"Bye," Rose smiled, stepping into the TARDIS and taking off her rucksack. She smiled as she watched the Doctor and the Alchemist work in sync to fly the TARDIS, both of them happier than she'd seen them both in a long time. They'd told her that morning about the Bonding they'd formed, and she'd grinned so widely she'd been afraid she'd split her face. That was followed by a huge Tyler hug, nearly squeezing them to death. Apparently, teasing had paid off . . . or the Doctor had finally come to his senses. "So where are we going?" she asked.

"Further than we're ever gone before," the Doctor answered.

"Dramatic much?" the Alchemist joked, flipping a lever.

He gave her a look. "Do you want me to be more dramatic?" he quipped.

She raised an eyebrow. "How dramatic would that be?"

Rose cleared her throat. "How about when there's not another human in the room?" she offered.

They both grinned in reply, and the Alchemist flipped another lever to land them. The Doctor held open the door, and Rose's jaw dropped when she stepped outside, seeing cars flying above them. "It's the year five billion and twenty three," the Doctor explained, stepping out behind the Alchemist. "We're in the galaxy M87, and this? This is New Earth."

"That's just . . . " Rose spun in a circle, jaw still hanging open. "That's just . . . "

"Not bad," the Doctor agreed, hands in his pockets as he looked around as well. "Not bad at all!"

"That's amazing!" Rose gushed as the Alchemist smiled. "I'll never get used to this. Never! Different ground beneath my feet, different sky . . . " She sniffed. "What's that smell?"

The Alchemist crouched down and tugged some of the grass from the ground, taking a whiff. "Apple grass," she answered, holding it up.

"Apple grass," Rose repeated incredulously.

"Yeah," the Alchemist grinned.

"It's beautiful!" Rose laughed, pulling her up to tug her into a hug, bringing the Doctor in a moment later. "Oh, I love this! Can I just say, traveling with you . . . " She beamed. "I love it."

"Me, too," the Doctor smiled before he took the Alchemist's hand. "Come on!"

The Alchemist laughed, grabbing Rose's hand to tug her after them as they took off running.

***

"So, the year five billion," the Doctor was saying as they laid back on his long coat, well, Rose and the Alchemist were laying, the Alchemist had her head in the Doctor's lap, and he was playing with her hair absently as he talked. "The sun expands, the Earth gets roasted."

"That was our first trip," Rose smiled, remembering.

"We had chips," the Doctor nodded. "So, anyway, planet gone, all rocks and dust, but the human race lives on, spread out across the stars. Soon as the Earth burns up, oh, yeah, they get all nostalgic, big revival movement, but then find this place."

"It's the same size as the Earth, with the same air and the same orbit," the Alchemist pitched in, finishing where the Doctor left off. "It's lovely. The call went out, and the humans moved in."

"What's the city called?" Rose asked, nodding at the huge city across the river.

"New New York," the Doctor answered.

Rose scoffed. "Oh, come on!"

"It is!" the Doctor insisted. "It's the city of New New York. Strictly speaking, it's the fifteenth New York since the original, so that makes it . . . " He thought about it. "New New New New New New New New New New New New New New York - " He cut off when the Alchemist chuckled, and he looked at her playfully. "What?"

"How long since we landed did you want to say that?" she asked.

The Doctor smirked. "A while."

"Knew it."

"You're so different," Rose smiled.

The Doctor shrugged. "New New Doctor."

Rose nodded at the city again. "Can we go and visit New New York, so good they named it twice?"

"Well, I thought we might go there first," the Doctor said, pointing to a pair of curved skyscrapers as he stood, holding out a hand to help the Alchemist up. Unlike times in the past, she accepted it, but neither let go once they stood.

"Why?" Rose asked, standing as well. "What is it?"

"It's a hospital," the Alchemist answered. "Do you see the green moon on the side?" Rose nodded. "That's the universal symbol for hospitals."

"And I got this," the Doctor added, pulling out his psychic paper. "A message on the psychic paper." Ward 26. Please come. "Someone wants to see me."

"Hmm," Rose pursed her lips. "And I thought we were just sight-seeing." She beamed. "Come on, then! Let's go and buy some grapes!"

***

"So you're a doctor, and you don't like hospitals?" Rose asked as they entered the building.

"It's the Doctor, thank you very much," the Doctor huffed, ignoring the Alchemist's giggling. "And no, I don't, really."

"Bit rich, coming from you," Rose smirked.

"I can't help it!" the Doctor whined. "I don't like hospitals! They give me the creeps."

"Seventh version of him," the Alchemist felt inclined to explain, smiling sadly as she found the memories in his mind. "Died in a hospital. They found his second heart and tried to remove it."

"Oh," Rose whispered. "I'm sorry."

The Doctor shrugged. "'S fine, really. The night guard was watching Frankenstein when I regenerated. Gave him a bit of a spook." He grinned. "Worth it."

"The Pleasure Gardens will now take visitors carrying green or blue identification cards for the next fifteen minutes. Visitors are reminded that cuttings from the gardens are not permitted."

"Very smart," Rose observed, looking around. "Not exactly NHS."

"No shop," the Doctor complained, pouting as he looked around as well. "I like the little shop."

"Why do you like a little shop?" the Alchemist asked with a smile.

"No souvenirs," he answered.

"I thought this far in the future, they'd have cured everything," Rose thought out loud.

"The human race moves on, but so do the viruses," the Doctor explained. "It's an ongoing war."

Rose nodded, following them, but she stopped to stare as one of the nurses passed. "They're cats," she realized.

"Now, don't stare," the Doctor admonished. "Think what you look like to them, all pink and yellow." Rose raised an eyebrow at him. "That's where I'd put the shop," he said quickly, pointing. "Right there."

The Alchemist called one of the lifts and stepped inside with the Doctor. "Ward 26, thanks!" she called.

The doors slammed shut before Rose could get in. "Hold on!" she called. "Hold on!"

"Oh, too late," the Doctor told her. "We're going up."

"It's all right, there's another lift."

"Ward 26, and watch out for the disinfectant."

"Watch out for what?"

"The disinfectant!"

"The what?"

"The disin - " He sighed. "Oh, you'll find out."

"Commence stage one disinfection."

The Alchemist had been expecting it, but she still squealed a bit when she was drenched by the disinfectant spray poured on her. The Doctor laughed, tilting his head, getting the spray everywhere, and the Alchemist pouted. "Of course you're enjoying it," she grumbled. "You're the pretty boy now."

"Pretty enough for you, Namara?" he asked with a smile.

She grinned. "Oh, yes."

He full out grinned as well as they were blow dried next. Both of them made a mess of their hair getting the spray out of it, and when the doors opened, the Alchemist quickly made sure hers looked all right before she followed the Doctor out.

"Please report to reception."

She caught up to the Doctor and snaked her arm around his as they followed one of the nurses through the ward. "Nice place," the Doctor complimented, smiling at the Alchemist as they walked. "No shop downstairs. I'd have a shop. Not a big one. Just a shop, so people can . . . shop."

The nurse turned and lowered her veil. "The hospital is a place of healing," she told him.

"A shop does some people the world of good," the Doctor shrugged. "Not me. Other people."

"The Sisters of Plentitude take a lifelong vow to help, and to mend," the sister told him.

"Excuse me!" a short voice shouted from nearby, and they turned as they passed an open bed, seeing a heavy man lying in bed, the woman with him glaring. "Members of the public may only gaze upon the Duke of Manhattan with written permission from the Senate of New New York."

The Alchemist blinked. "Is that Petrifold Regression?"

"I'm dying, ma'am," the Duke told her hoarsely. "A lifetime of charity and abstinence, and it ends like this."

"Any statements made by the Duke of Manhattan may not be made public without official clearance," the woman added.

"Frau Clovis!" the Duke groaned. "I'm so weak!"

Clovis glared at the sister. "Sister Jatt? A little privacy, please."

Jatt closed the curtain around them and continued on. "He'll be up and about in no time."

The Alchemist blinked. "That's Petrifold Regression," she said slowly. "He's turning to stone! And there's no cure for at least a thousand years! Up and about? Maybe. Do you need a statue?"

"Have faith in the Sisterhood," Jatt told her with a mysterious smile. "But is there no one here you recognize? It's rather unusual to visit without knowing the patient."

The Alchemist was about to shake her head when the Doctor saw something over her shoulder. "No," he swallowed. "I think I've found him."

The Alchemist turned to see him staring at a huge face in a glass container by the window. "Novice Hame?" Jatt asked the cat nun by the container. "If I can leave these two in your care?"

"Oh, I think our friend got lost," the Doctor told Jatt as she turned to go. "Rose Tyler. Could you ask at reception?"

"Certainly, sir," Jatt bowed, then turned to leave.

Novice Hame smiled as they approached. "I'm afraid the Face of Boe's asleep," she told them. "That's all he tends to do these days. Are you friends, or - ?"

"I met him just once, on Platform One," the Doctor answered, gazing at the Face of Boe with a smile. "What's wrong with him?"

"I'm so sorry," Hame said, the smile slipping off of her face. "I thought you knew. The Face of Boe is dying."

"What of?" the Alchemist asked gently.

"Old age," Hame answered sadly. "The one thing we can't cure. He's thousands of years old. Some people say millions, although that's impossible."

"Oh, I don't know," the Doctor shrugged. "I like impossible." He crouched next to the container, the Alchemist going down with him, her hand on his shoulder. "I'm here," he whispered, putting a hand to the glass. "I look a bit different, but it's me. It's the Doctor."

***

"Hope, harmony, and health. Hope, harmony, and health."

The Alchemist smiled as the Doctor brought both of them glasses of water. "Thanks, Kasterborous," she told him.

He beamed at the use of his name. "You're welcome, Namara."

"That's very kind," Hame said as he handed her the other glass. "There's no need."

"You're the one working," the Doctor pointed out, sitting down next to the Alchemist.

"There's not much to do," Hame shook her head. "Just maintain his smoke. And I suppose I"m company. I can hear him singing, sometimes, in my mind. Such ancient songs."

"Are we the only visitors?" the Alchemist asked.

"The rest of Boe-kind became extinct long ago," Hame told her. "He's the only one left. Legend says that the Face of Boe has watched the universe grow old. There's all sorts of superstitions around him. One story says that just before his death, the Face of Boe will impart his great secret, that he will speak those words only to one like himself."

"What does that mean?"

"It's just a story."

"I like stories. Tell us the rest."

Hame sighed. "It's said he'll talk to a wanderer. To the man without a home. The lonely God."

The Alchemist turned to the Doctor, seeing him straighten up. That sounded exactly like him.

"Except for one detail," he said telepathically, looking at her. "I do have a home."

"We have the TARDIS," she agreed.

"No." She blinked, and he smiled. "You. Wherever you are, it's home."

She blushed. "Who are you, and what happened to the Doctor?"

He grinned. "I told you. New New Doctor."

"No kidding."

"Are you complaining?"

"Do you hear me complaining?"

The Doctor shook his head with a smile before he stood up. "I'm going to find Rose," he told her out loud. "Coming?"

She nodded and stood with him, and they headed over to reception. "Can we use the phone real quick?" she asked.

The sister at reception nodded, and the Doctor dialed Rose's number. When she picked up, the Doctor asked, "Rose, where are you?"

There was a pause, then Rose answered a bit stiffly, "Er, wotcha!"

"Where've you been?" the Doctor asked, not seeing the Alchemist narrow her eyes suspiciously. "How long does it take to get to Ward 26?"

"I'm on my way, governor," Rose answered, her voice thickly English. "I shall proceed up the apples and pears!"

The Alchemist frowned visibly now. That just wasn't Rose. "You'll never guess," the Doctor continued, either not noticing or not indicating that he did. "We're with the Face of Boe! Remember him?"

"Of course I do," she answered before grumbling quietly, "That big old boat race."

The Alchemist frowned and was about to say something when her eyes widened. "We'd better go," she said, taking the phone. "See you soon."

She put the phone down, then headed over to the Duke of Manhattan's bunk. The man was sitting up, laughing, completely cured! "Didn't think I was going to make it," the Duke was saying before he brightened when he saw the Alchemist. "It's that woman again! She's my good luck charm! Come in, don't be shy!"

"And she's taken," the Doctor warned, taking her hand, but he approached as well.

"Any friendship expressed by the Duke of Manhattan does not constitute a form of legal contract," Clovis told them.

"Champagne, sir?" a waiter asked. "Madam?"

"No, thanks," the Doctor shook his head. "You had Petrifold Regression, right?"

"That being the operative word," the Duke smiled. "Past tense. Completely cured."

"That's impossible," the Alchemist deadpanned.

"Primitive species would accuse us of magic," a nun behind them said, and they turned as the cat nurse in charge approached. "But it's merely the tender application of science."

"How on Earth did you cure him?" the Doctor asked.

She smiled. "How on New Earth, you might say."

"Very funny," the Alchemist rolled her eyes before eyeing the drip bag hanging from a hook. "What's in that solution?"

"A simple remedy."

"Care to tell us what it is?"

"I'm sorry, patient confidentiality. I don't believe we've met. My name is Matron Casp."

"I'm the Doctor, and this is my Bonded, the Alchemist," the Doctor introduced themselves, the Alchemist beaming at how he introduced her.

Casp curled her lip. "I think you'll find that we're the doctors here."

Jatt came up and tapped her on the shoulder. "Matron Casp, you're needed in Intensive Care."

Casp nodded politely. "If you would excuse me."

The Doctor nodded and watched them go. "Come to think of it, did we see an Intensive Care?" he asked the Alchemist.

She shook her head. "No . . . we haven't."

***

The Alchemist was inspecting more of the patients when Rose finally emerged from the lifts. "There you are!" the Doctor cheered, going over to her and pulling her over. "Come and look at this patient!"

"Marconi's Disease," the Alchemist nodded. "It should take years to recover, and this took two days!"

"I've never seen anything like it!" the Doctor added. "They've invented a cell washing cascade. It's amazing! Their medical science is way advanced. And this one!"

The Alchemist nodded at the man as white as his gown. "Pallidome Pancrosis," she diagnosed. "Should kill you in ten minutes, but he's completely fine."

"We need to find a terminal," the Doctor decided, looking around. "I've got to see how they do this. Because if they've got the best medicine in the world, then why is it such a secret?"

"I can't Adam and Eve it," Rose nodded.

The Doctor blinked, looking at her. "What's, what's . . . what's with the voice?"

"Oh, I don't know," Rose shrugged, beginning to look him over, the Alchemist narrowing her eyes. This didn't seem like Rose at all. She knew about them . . . so why was she looking like she wanted to jump her Bonded? "Just larking about. New Earth, new me."

"Well, I can talk," the Doctor grinned. "New New Doctor."

"Mmm," Rose grinned. "Aren't you just?"

And then she grabbed him and kissed him, long and hard. The Alchemist's eyes widened in shock and surprise, before they abruptly narrowed, and she stalked forward, putting one hand on the Doctor's shoulder, and she used her other one to shove Rose away. She stumbled back, eyes wide as she looked at the Alchemist, the woman actually seeming to growl as the Doctor blinked, seemingly stunned as well. "What the hell?" the Alchemist snapped.

Rose swallowed. "T . . . terminal's this way," she offered, pointing behind her, heading in that direction.

The Alchemist narrowed her eyes. "That is not Rose," she sneered, folding her arms.

The Doctor swallowed. "You know I didn't - "

"You didn't kiss her back," the Alchemist nodded. "I know."

The Doctor nodded. "Right . . . " He took her hand, squeezing it, before he followed not-Rose.

***

"Nope, nothing odd," the Doctor shook his head as he examined the blueprints of the building. "Surgery, post-op, nano-dentistry. No sign of a shop. They should have a shop!"

"No, it's missing something else," Rose shook her head. "When I was downstairs, those Nurse Cat Nuns were talking about Intensive Care. Where is it?"

The Alchemist nodded, looking it over. "It's not on here. Nice job."

"Why would they hide a whole department?" Rose wondered. "It's got to be there somewhere. Search the sub-frame."

The Alchemist raised an eyebrow. Rose couldn't have known that. "What if the sub-frame's locked?" she challenged.

"Try the installation protocol," Rose answered in a "duh" voice.

The Doctor nodded slowly, more suspicious than ever. "Yeah," he said slowly. "Of course. Sorry. Hold on."

He sonicked the terminal, and the Alchemist raised the other eyebrow as the entire wall slid down, revealing the darkened corridor it had been hiding. "Well, that certainly looks Intensive," she quipped.

Rose led the way down the corridor and down an old-fashioned staircase. The Alchemist frowned, looking around the corridors, seeing cells that reminded her of Cybermen holding cells. Curious, she opened one, and her jaw dropped when she saw the very sick man inside. "Oh, my God," she gagged.

"That's disgusting!" Rose gasped, looking over her shoulder at the man. "What's wrong with him?"

The Doctor just looked sympathetic. "I'm sorry," he whispered. "I'm so sorry."

The Alchemist shut the door, looking like she wanted to throw up. "Is it all of them?" she whispered, horrified, as she checked the next one.

The woman inside looked just the same. "What disease is that?" Rose asked.

"All of them," the Alchemist breathed. "Every single disease in the galaxy. They've been infected with everything!"

"What about us?" Rose asked. "Are we safe?"

"The air's sterile," the Doctor nodded, gently prying the Alchemist's white fingers from the door and closing the door himself. "Just don't touch them."

"How many patients are there?" Rose asked, looking around.

"They're not patients," the Doctor said darkly.

"But they're sick!"

"They were born sick," the Doctor corrected, putting an arm around the Alchemist. "They're meant to be sick. They exist to be sick. Lab rats." He shook his head in disgust. "No wonder the Sisters have got a cure for everything. They've built the ultimate research laboratory. A human farm."

"Why don't they just die?" Rose asked.

"Plague carriers," the Alchemist whispered, looking a bit green. "The last to go."

"It's for the greater cause," a voice behind them said.

"Novice Hame," the Doctor said, turning to her. "When you took your vows, did you agree to this?"

"The Sisterhood has sworn to help," Hame answered, dodging and answering the question at the same time.

"By killing?" the Alchemist asked in disgust.

"But they're not real people," Hame tried to explain. "They're specially grown. They have no proper existence."

"So what's the turnover?" the Alchemist asked angrily. She'd seen hundreds of diseased people in her time as a representative, seen many of these diseases, and to see innocent people infected with every single one . . . she really did want to throw up. "Is it a thousand a day? Thousand the next? Thousand the next? How many thousands has it been? How many years? Tell us!"

"Calm down, Namara," the Doctor soothed, putting a hand on her arm, only feeling her slightly relax.

"Mankind needed us," Hame told her, swallowing a bit at the threat. "They came to this planet with so many illnesses. We couldn't cope. We did try. We tried everything. We tried using clone-meat and bio-cattle, but the results were too slow, so the Sisterhood grew its own flesh. That's all they are. Flesh."

"These people are alive!" the Doctor protested.

"But think of those Humans out there," Hame insisted desperately. "Healthy and happy because of us!"

"If they live because of this, then life is worthless," the Doctor said bluntly.

"But who are you to decide that?"

"I'm the Doctor," he answered. "And if my Bonded doesn't like this, then I definitely don't. If you don't like it, if you want to take it to a higher authority, then there isn't one. It stops with me."

Rose poked her head around the Time Lords. "Just to confirm, none of the humans in the city actually know about this?"

"We thought it best not," Hame shook her head.

"So here's the thing I'm not understanding," the Alchemist held up a hand. "I can understand the bodies, and I can understand your vows. The one thing I don't understand . . . is what have you done to Rose?"

Hame blinked. "I don't know what you mean."

"Oh, you don't?" the Alchemist chuckled darkly. "The brain is a delicate thing, because I know Rose wouldn't kiss my Bonded."

"We haven't done anything!"

"I'm perfectly fine," Rose sniffed.

The Doctor raised an eyebrow at her. "Only Alice kisses me," he told her. "And these people are dying. Rose would care."

Rose glared, then sighed. "Oh, all right. Clever clogs. Smarty pants." She gave him a flirty look. "Lady killer."

"What's happened to you?" the Doctor asked with a frown.

"I knew something was going on in this hospital, but I needed this body and your mind to find it out."

"Who are you?"

Rose smiled flirtatiously. "The last human."

"Who?" the Alchemist blinked.

The Doctor's eyes widened. "Cassandra?"

Rose smirked. "Wake up and smell the perfume," she said sweetly, whipping a vial from inside her shirt and squirting it up his nose. The Doctor's eyes rolled up into his head, and he collapsed.

The Alchemist's eyes widened. "What the - ?" she began, reaching out to grab the vial, but Cassandra grabbed her wrist with her free hand. After a bit of a struggle, Cassandra finally managed to get the contents of the vial up the Alchemist's nose, too, and she collapsed right next to the Doctor.

***

The Doctor woke up to find himself in one of the cells, and he straightened quickly to see the Alchemist banging on the door of another cell. "Let me out!" he shouted. "Let me out!"

Cassandra poked her head in through the window. "Aren't you lucky there were spares?" she grinned. "Standing room only."

"You've stolen Rose's body," the Doctor accused, "and shoved my Bonded into a holding cell!"

"Over the years, I've thought of a thousand ways to kill you, Doctor," Cassandra ignored him. "And now, that's exactly what I've got. One thousand diseases. They pump the patients with a top-up every ten minutes. You've got about three minutes left. Enjoy!"

"Just let Rose and the Alchemist go, Cassandra," the Doctor ordered.

"I will . . . as soon as I've found someone younger, and less common, then I'll junk her with the waste." The Doctor opened his mouth angrily, but Cassandra held up a finger. "Now, hushaby. It's showtime!"

"Anything we can do to help?" Jatt's voice asked.

"Straight to the point, Whiskers," Cassandra answered. "I want money."

"The Sisterhood is a charity," Casp told her. "We don't give money. We only accept."

"The humans across the water pay you a fortune, and that's exactly what I need. A one-off payment, that's all I want. Oh, and perhaps a yacht. In return for which, I shall tell the city nothing of your institutional murder. Is that a deal?"

"I'm afraid not."

Cassandra narrowed her eyes. "I'd really advise you to think about this."

"Oh, there's no need. I have to decline."

"I'll tell them, and you've no way of stopping me! You're not exactly Nuns with Guns. You're not even armed!"

"Who needs arms when we have claws?" Casp sneered, unsheathing her own.

Cassandra nodded. "Well, nice try." She turned to the sepia-patterned man behind her. "Chip? Plan B!"

The door suddenly opened, and the Doctor ran out, the Alchemist doing the same thing . . . along with lots of the diseased people. "What've you done?" the Doctor shouted at Cassandra.

"Gave the system a shot of adrenaline, just to wake them up," Cassandra answered. "See you!"

The Doctor growled as Cassandra and Chip took off. "Don't touch them!" he ordered the cats. "Whatever you do, don't touch!"

They ran down the stairs and across the catwalk, but Cassandra froze when all of the cells opened, and the diseased people all walked free. "Oh, my God," she breathed.

"What the hell have you done?" the Doctor shouted.

"It wasn't me!"

"One touch, and you get every disease in the world, and I want that body safe, Cassandra!" the Doctor barked. "We've got to go down!"

"But there's thousands of them!"

"Move it, lady!" the Alchemist ordered. "Or do you want me to shove you down there?"

Cassandra quickly took off, the others behind her.

"This building is under quarantine. Repeat, this building is under quarantine. No one may leave the premises. Repeat, no one may leave the premises."

The Alchemist shook her head as Cassandra ran for the lifts. "The lifts have closed down. With quarantine, nothing's moving."

"This way!" Cassandra pointed.

They ran, but Chip was cut off. "Someone's going to touch him!" the Alchemist shouted.

"Leave him!" Cassandra snapped. "He's just a clone thing. He's only got a half life. Come on!"

"Mistress!" Chip pleaded.

The Doctor shook his head. "We can't let her escape," he apologized, taking off after Cassandra.

"My Mistress!"

The Doctor arrived to see Cassandra and the Alchemist slamming a door closed. "We're trapped!" Cassandra wailed. "What am I going to do?"

"Well, for starters, you're going to leave that body," the Doctor answered, narrowing his eyes. "That psychograft is banned on every civilized planet1 You're compressing Rose to death!"

"But I've got nowhere to go!" Cassandra pleaded. "My original skin's dead."

"Not my problem," the Doctor said bluntly. "You can float as atoms in the air. Now, get out. Give her back to us!"

Cassandra sighed. "You asked for it."

The Alchemist blinked when energy flew out of Rose's mouth, and she ran forward to steady her again. "Rose?" she asked.

"Blimey, my head," Rose groaned, putting her hands to her head before she shook it and looked around. "Where'd she go?"

"Oh, my." Both of them looked at each other before turning to the Doctor, who was looking himself over oddly. "This is different."

The Alchemist's jaw dropped as Rose squeaked, "Cassandra?"

"Goodness me, I'm a man," Cassandra/Doctor said with a grin. "Yum! So many parts! And hardly used." He blinked, jerking a bit. "Oh. Oh! Two hearts! Oh, baby, I'm beating out a samba!"

"Is it bad that I'm enjoying this and not at the same time?" the Alchemist asked.

"No idea," Rose answered before saying, "Get out of him!"

"Oh, he's slim, and a little bit foxy." Cassandra/Doctor smirked. "You've thought so, too. I've been inside your head. You've been looking. You like it."

The Alchemist looked at Rose, who shook her head desperately. "It was after he regenerated," she pleaded. "I swear, that was it!"

The Alchemist began to say something when the diseased people broke in through the door, making Cassandra/Doctor panic. "What do we do?" he asked desperately. "What would he do? The Doctor, what the hell would he do?"

"Ladder," the Alchemist answered, pointing. "Get up."

"Out of the way, raven!" Cassandra/Doctor ordered, pushing her away and getting up the ladder.

"Oi!" the Alchemist frowned. "Raven?"

"Hair," Rose answered as they climbed before shouting at Cassandra/Doctor. "If you get out of the Doctor's body, he can think of something!"

"Yap, yap, yap," Cassandra/Doctor rolled his eyes. "God, it was tedious inside your head. Hormone city!"

"We're going to die if - " Rose yelped, and the Alchemist looked down to see Matron Casp had followed them, and had grabbed Rose's ankle. "Get off!" Rose shouted.

"All our good work," Casp accused. "All that healing. The good name of the Sisterhood. You have destroyed everything!"

"Go and play with a ball of string!" Cassandra/Doctor huffed.

"Everywhere, disease. This is the human world. Sickness!"

A hand grabbed Casp's ankle, and she fell, yowling. "Move!" the Alchemist shouted.

"Maximum quarantine. Divert all shuttles."

"Now what do we do?" Cassandra/Doctor huffed when the door wouldn't open.

"Use the sonic screwdriver!" Rose shouted.

Cassandra/Doctor pulled it out. "You mean this thing?"

"Yes, I mean that thing!"

"Well, I don't know how. The Doctor's hidden away all his thoughts."

"Well, I wonder why!" the Alchemist rolled her eyes.

"Cassandra, go back into me," Rose ordered. "The Doctor can open it. Do it!"

"Hold on tight," Cassandra/Doctor answered.

The Alchemist watched the energy transfer. "Oh, chavtastic again," Cassandra/Rose rolled her eyes before shouting at the Doctor, "Open it!"

"Not till you get out of her!" the Doctor snapped back.

"Lovely," the Alchemist sighed, rubbing her forehead.

"We need the Doctor!"

"I order you to leave her!"

"Seriously?" the Alchemist groaned as the energy swapped again.

"No matter how difficult the situation, there is no need to shout," Cassandra/Doctor rolled his eyes.

"Cassandra, get out of him!" Rose ordered.

"But I can't go into you. He simply refuses! He's so rude."

"I don't care," Rose snapped. "Just do something!"

The Doctor shook his head when the energy left him, but then the Alchemist let out a startled noise. "Well, this is different," Cassandra/Alchemist remarked, looking herself over. "Oh, she's got a thing for skin tight, doesn't she? It's no wonder you chose the suit. Did you take it after her?"

"Get out of her!" the Doctor shouted, more angry than ever.

"Well, I can't go into either of you!" Cassandra/Alchemist huffed. "You simply refuse either way!"

"Get out of my Bonded!" the Doctor demanded, eyes flashing angrily.

Cassandra/Alchemist sighed. "Oh, I am so going to regret this."

The Alchemist nearly fell from the ladder when Cassandra left her, and would have fallen had Rose not reached up to put a hand on her back to support her. They looked down to see the lead woman on the ladder look herself over. "Oh, sweet Lord," Cassandra groaned. "I look disgusting!"

The Doctor finally got the lift doors open and smiled. "Nice to have you back."

"No, you don't!" Cassandra shouted, and just before the lift doors closed, the energy swooped back to Rose.

The Doctor narrowed his eyes. "That was your last warning, Cassandra!"

But Cassandra looked horrified. "Inside her head," she whispered. "They're so alone. They keep reaching out, just to hold us. All their lives, and they've never been touched."

The Doctor took the Alchemist's hand and offered Cassandra the other. She took it, and they headed out -

And were nearly clobbered with Clovis's metal stand. "We're safe!" the Doctor shouted, holding up his hands. "We're safe! We're clean! We're clean! Look, look!"

"Show me your skin," Clovis ordered.

"If we'd been touched, we'd be dead," the Alchemist told her shortly. "You going to argue with that?"

"What's the status?" the Doctor asked.

"There's nothing but silence from the other wards," Clovis answered, looking at them warily. "I think we're the only ones left. And I've been trying to override the quarantine. If I can trip a signal over to New New York, they can send a private executive squad."

"You can't do that! If they forced entry, they'd break quarantine!"

"I am not dying here!"

"We can't let a single particle of disease get out. There is ten million people in that city. They'd all be at risk." He nodded at the terminal. "Now, turn that off!"

"Not if it gets me out!"

The Alchemist rolled her eyes and used the stand to hit Clovis in the back of the head, knocking her out. "There. Sorted."

The Doctor shook his head fondly before shouting to the others. "Rose, Novice Hame, everyone!" he called. "Excuse me, Your Grace," he added, scooting past the Duke. "Get me intravenous solutions for every single disease. Move it!"

Everyone pitched in to hand drip bags to the Doctor, who threaded them on heavy silk rope and wrapped them around his body. "How's that?" he asked the Alchemist. "Will that do?"

"I hope," she answered.

"I don't know," Cassandra shrugged. "Will it do for what?" The Doctor simply sonicked the lift doors open. "The lifts aren't working."

"They're not moving," the Alchemist corrected. "There's a difference." She bounced on the heels of her feet. "Here we go."

"But you're not going to - !"

The Alchemist took a running jump and grabbed the lift cable, wrapping herself around it. "Nice!" the Doctor grinned.

"What do you think you're doing?" Cassandra shrieked as the Alchemist fastened a round wheel to the cable, the Doctor jumping onto the cable after her.

"Going down!" the Alchemist answered. "Come on!"

"Not in a million years!"

"We need another pair of hands," the Doctor told her. "What do you think? If you're so desperate to stay alive, why don't you live a little?"

"Seal the door!" one of the cats ordered.

Cassandra's eyes widened as she was stuck with the approaching diseased people. "No!" she gasped, jumping onto the Doctor's back. "You're completely mad." She grinned. "I can see why the Alchemist likes you."

The Doctor grinned smugly as the Alchemist blushed. "Going down!" he warned, setting the wheel in motion.

They slid down the shaft, and the Alchemist landed them down on top of the lift. "Well, that's one way to lose weight," Cassandra breathed, jumping off.

"Now, listen," the Doctor told her, pointing at a lever. "When I say so, take hold of that lever."

"There's still a quarantine down there," Cassandra pointed out. "We can't - "

"Hold that lever," the Doctor ordered as the Alchemist started pouring the drip bags into the disinfectant tank. "We're cooking up a cocktail. I know a bit about medicine myself, and Alice here is the best one to make it. Now, that lever's going to resist, but both of you, keep it in position. Hold onto it with everything you've got."

"What about you?" Cassandra asked.

The Doctor just opened the hatch into the lift. "I've got an appointment," he grinned. "The Doctor is in!" He dropped down into the lift and opened the doors. "I'm in here!" he called. "Come on!"

"Don't tell them!" Cassandra shouted.

"Pull that lever!" The Alchemist pulled the lever down with Cassandra, both of them straining to keep it down. "Come and get me! Come on! I'm in here! Come on!"

"Commence stage one disinfection."

"Hurry up! Come on!"

The Alchemist poked her head down and watched the contents of the tank pour on top of the Doctor, and onto the diseased people that had stepped inside. "Good job!" she called to him.

"Pass it on," the Doctor urged the now healed people. "Pass it on!"

"Pass on what?" Cassandra asked, trying to see. "Pass on what?"

"Pass it on!" the Doctor urged.

There were hisses as the cures were passed, then he helped the Alchemist and Cassandra down. "What did they pass on?" Cassandra asked. "Did you kill them? All of them?"

"No," the Doctor shook his head, stepping out of the lift. "That's your way of doing things." He smiled proudly, watching as the cured people spread the cures around. "I'm the Doctor, and I cured them!"

The Alchemist smiled as a woman walked up and hugged her. "There you go, sweetheart," she smiled, giving her a hug as well. "Hey, go to him," she urged, pointing to a sick man hobbling forward. "Go on. That's it." She smiled as the woman walked over and touched him, the cures healing the man as well. "Meet a new sub-species, Cassandra."

"A brand new form of life," the Doctor beamed. "New humans! Look at them, look! Grown by cats, kept in the dark, fed by tubes, but completely, completely alive! You can't deny them because you helped create them. The human race just keeps on going, keeps on changing. Life will out!" He hugged the Alchemist gleefully. "Ha!"

***

"This is the NNYPD. Please step away from the shuttles."

"All staff will present themselves to the officers for immediate arrest. I repeat, immediate arrest. All new life forms will be catalogued and taken into care. All visitors to the hospital will be required to make a statement to the NNYPD."

The Alchemist's eyes widened as they stepped back into Ward 26. "Doctor," she breathed, pointing.

The Doctor's eyes widened. "The Face of Boe!" Boe's eyes opened as the two Time Lords ran over, Cassandra following. "You were supposed to be dying!"

"There are better things to do today," Boe told him. "Dying can wait."

"Oh, I hate telepathy," Cassandra grumbled. "Just what I need! A head full of face."

"Shush," the Alchemist ordered.

"I have grown tired of the universe, Doctor," Boe told him. "But you and your Bonded have taught me to look at it anew."

"There are legends, you know, saying that you're millions of years old," the Doctor told him.

"There are?" Boe sounded amused at that. "That would be impossible."

"Wouldn't it just," the Doctor smiled. "I got the impression there was something you wanted to tell me."

"A great secret."

"So the legend says."

"It can wait."

"Oh, does it have to?" the Doctor whined.

"We shall meet again, Doctor, Alchemist, for the third time, for the second time, for the last time, and the truth shall be told. You have overcome one obstacle, but more are coming, one far worse than you could ever imagine." The Doctor and the Alchemist looked at each other uneasily. "One that has the capability to tear you further apart than ever before. Until that last day."

"I hate enigmatic," the Alchemist managed to say as the Face of Boe teleported away.

"That is textbook enigmatic," the Doctor nodded, wondering what obstacle was coming that could tear them apart more than when they'd found each other. He turned to Cassandra, that could wait for later, though. "And now for you."

Cassandra blinked, almost surprised that they hadn't forgotten about her. "But everything's happy! Everything's fine! Can't you just leave me?"

"You've lived long enough," the Doctor told her. "Leave that body and end it, Cassandra."

Cassandra's lip quivered. "I don't want to die."

"No one does," the Alchemist told her.

"Help me."

"We can't," the Time Lords said in unison.

"Mistress!" a familiar voice called.

Cassandra rolled her eyes as Chip ran up. "Oh, you're alive," she grumbled, almost disappointed.

"I kept myself safe for you, mistress," Chip told her.

And suddenly, Cassandra was very interested. "A body," she admired. "And not just that . . . a volunteer."

"Don't you dare," the Doctor warned. "He's got a life of his own!"

"But I worship the mistress," Chip told him. "I welcome her."

"You can't, Cassandra," the Doctor shook his head. "You - " But the energy swirled from Rose to Chip, and she collapsed. "Oh!" the Doctor exclaimed, catching Rose quickly. "You all right? Whoa! OK?"

"Yeah," Rose nodded wearily, straightening before beaming. "Hello!"

"Hello," the Doctor grinned. "Welcome back."

"Oh, sweet Lord." The three of them turned to Cassandra/Chip to see him looking over himself. "I'm a walking doodle."

"You can't stay in there," the Doctor told him, crouching by him, the Alchemist and Rose at his shoulders. "I'm sorry, Cassandra, but that's not fair. I can take you to the city. They can build you a skin tank, and you can stand trial for what you've done."

"Well, that would be rather dramatic," Cassandra/Chip quipped. "Possibly my finest hour, and certainly my finest hat, but I'm afraid we don't have time. Poor little Chip is only a half-life, and he's been through so much. His heart is racing so. He's failing. I don't think he's going to last - "

He fell forward, and the Alchemist quickly reached out to steady him. "All right there?"

"I'm fine," Cassandra/Chip whispered. "I'm dying . . . but that's fine."

"We can take you to the city," the Doctor began.

"No, you won't," Cassandra/Chip shook his head. "Everything's new on this planet. There's no place for Chip and me any more. You're right, Doctor. It's time to die, and that's good."

The Alchemist tilted her head. "Still . . . there's one last thing we can do."

***

The Doctor's eyes widened when he looked around where the Alchemist had landed. "You," he told her, "are incredible."

She smiled. "I try."

Cassandra/Chip shook his head, looking at them. "Thank you," he breathed.

"Just go," the Alchemist smiled. "And don't look back."

"Good luck," Rose smiled.

Cassandra/Chip nodded and turned to walk over to Cassandra when she was still normal. They watched the two interact, then Cassandra/Chip fell forward. They silently filed back into the TARDIS, and the Doctor sent her flying.

Rose bit her lip, leaning against one of the coral structures. The Alchemist tilted her head and walked over. "Are you feeling all right?" she asked. "Psychograft do anything?"

"No," Rose shook her head quickly. "No, I'm fine, it's just . . . " She blushed. "I kissed him."

The Alchemist's eyebrows shot up. "That was Cassandra, Rose," she reminded her. "That wasn't you."

"But it was still my body," Rose blushed even further. "And those thoughts in my head . . . Ali, I swear - "

"Rose, I'm not mad," the Alchemist laughed. "It takes more than a possessed sister kissing my Bonded to make me want to kill you."

Rose started to nod when she froze, her eyes wide at the last statement. " . . . Sister?" she breathed.

"Yeah," the Alchemist smiled. "My little sister." She tilted her head. "That all right?"

Rose grinned widely. "Yes!" she cheered, giving her friend - no, her big sister - a huge hug. "Oh, yes!"

The Alchemist grinned, hugging Rose back, not seeing the Doctor beam from where he stood by the console.

Oh, yes. He definitely loved this new beginning.

***

So now Rose joins the Harkness family! Jack, the Alchemist, and Rose. :) Rose won't "officially" be the Ninth Alchemist's sister, though. The Ninth is purely Jack's little sister. And I can say that one of the Ponds will be related in some way to the Alchemist. It might surprise you which one it is, though. ;) All I can say, when there's a kiss, there might be a slap instead.

But how about Boe's warning? What's the huge obstacle coming that could tear them apart? Well . . . all I can say is, savor these flirty/fluffy moments when you have them. }:)

I'll leave you on that cliffy. ;) Comment away!