In the boiler room they found what they were looking for.

"She's going to poison the air," the Doctor said.

"How?" Jenny asked.

A man pulled a lever to reveal the base of a rocket.

"With that, I should think," Clara said.

Two people pulled a sheet off something on the ground and there was a container with the red poison sitting in a basket.

"And there's the poison. All right, gang, I've got a plan," the Doctor said.

They stood up and something metal clattered to the ground. They quickly ducked down as the pilgrims turned to them.

"Okay."

They carefully stood up this time.

Elise followed Clara and her father and they came to a room where a woman was crying.

"Who is that? Who is there?" she asked.

The Doctor walked over to her and took her hand, running it over his face.

"You. It's you. My monster. You've come back. But you're..."

"Warm. And alive, thanks to you, Ada. You saved me from your mother's human rubbish tip." The Doctor cupped her face. "Now then, what's wrong?"

"She does not want me, monster. I am not to be chosen. Perhaps it was my own sin, the blackness in my heart that my father saw in me."

"Ada, no. That's nonsense. Stupid, backward nonsense, and you know it. You know it." He traced her scars with his thumb.

Elise walked over to them and placed her hand on Ada's.

"Who is that?" she asked.

"My name is Elise. Your monster is my father. I wanted to thank you for saving him."

"Your father?"

Elise laughed softly. "Yes. He may look young, but he really isn't."

"Then you are fortunate indeed. It isn't good to be alone."

"Now, Ada, I need you to tell me something. Who is Mister Sweet? Ada?" the Doctor asked.

"Oh, dear monster..."

"Please, tell me."

"I cannot. Even now, I cannot. I cannot betray Mama."

"Well, come with us, then. There's something you need to know." He stood up and led her by the arm to the drawing room.

Ada stood outside the room for the time being.

Mrs. Gillyflower laughed. "Oh, you do seem to keep turning up like a bad penny, young man."

"Force of habit."

"Can I offer you something? Tea? Seed cake? Oh, a glass of Amontillado?"

"No, thanks. We've had a skinful already, as you might say."

"Ha, ha. Very funny."

"Yes. I'm the Doctor, you're nuts and I'm going to stop you."

"I'm afraid Mister Sweet and I cannot allow that." Mrs. Gillyflower looked at Elise. "Well you're a pretty one, aren't you?"

Elise still had the sword in her hand and raised it in warning.

"Ah, not just a pretty face."

The Doctor put himself in between Mrs. Gillyflower and his daughter. "Would it be impolite to ask why you and Mister Sweet are petrifying your workforce with diluted prehistoric leech venom?"

"So when do we get to meet him, this silent partner of yours? Why's he so shy?" Clara asked.

"Mister Sweet is always with us," Mrs. Gillyflower told them.

"You seem to have a very close relationship, you and your pal," the Doctor said.

"Oh yes, Doctor. Exceedingly close. Symbiotic, you might say." She undid the top of her dress to reveal a large red leech attached to her chest.

"Doctor, what is it?" Clara asked.

"A survivor. He has grown fat on the filth humanity has pumped into the rivers. That's where I found him," Mrs. Gillyflower said.

"Very enterprising."

Elise was briefly reminded of the Great Intelligence and the Snowmen. She quickly rid herself of that thought. She'd regenerated during that trip, so it was a bittersweet memory.

"His needs are simple, and in return he gives me his nectar."

"Mrs. Gillyflower, you have no idea what you are dealing with. In the wrong hands, that venom could wipe out all life on this planet."

Mrs. Gillyflower held out her hands. "Do you know what these are?" She laughed maniacally. "The wrong hands!" She got up and went over to the control panel, pulling a lever.

"Planning a little fireworks party, are we?" the Doctor asked.

"You have forced me to advance the Great Work somewhat, Doctor, but my colossal scheme remains as it was. My rocket will explode high in the atmosphere, raining down Mister Sweet's beneficence onto all humanity."

"And wiping us all out. You can't!" Clara yelled.

The Doctor grabbed Clara before she reached Mrs. Gillyflower.

"My new Adam and Eves will sleep for but a few months before stepping out into a golden dawn. Is it not beautiful, Doctor?"

The Doctor clapped. "Now, tell us about Ada, Mrs. Gillyflower."

"What?"

"Your daughter. You do remember your daughter? Tell us about your daughter."

"How can you speak of such trivia when my hour is at hand? The child is of no consequence."

"No consequence? She's your daughter!" Elise snapped.

"Is that why you experimented on her?" the Doctor asked.

"Experimented?" Clara asked.

"The signs are all there. The pattern of scarring. You used her as a guinea pig, didn't you?"

Elise was disgusted by the woman.

"Sometimes sacrifices must be made," Mrs. Gillyflower said.

"Sacrifices?"

"It was necessary. I had to find out how much of the venom would produce an anti-toxin to immunize myself. Don't you see? It was necessary!"

"She's your own flesh and blood. How could you do that to her!" Elise yelled.

The Doctor stood up, putting himself between Elise and Mrs. Gillyflower. He grabbed Elise's arms and tried to calm her before she had one of her epic meltdowns. He couldn't afford for her own 'Oncoming Storm' to come out right now.

Ada entered the room. "Mama? Is it, is it true?" she asked.

"Ada..."

"It is. It's true. True."

"Ada, listen to me."

"You hag! You perfidious hag! You virago! You harpy! All these years I have helped you, served you, looked after you. Do they count for nothing, nothing at all?" Ada started hitting her mother with her stick.

"No, stop. Stop."

Clara ran forward and picked up a chair.

"Hang on, I've got a sonic screwdriver," the Doctor told her.

"Yeah? I've got a chair!" Clara smashed it into the control panel and it exploded, sparks shooting everywhere.

"No!" Mrs. Gillyflower yelled.

"Yeah. That worked. I'm afraid your rocket isn't going anywhere, Mrs G," the Doctor said.

"Please, come to me, Ada. Oh, my child." Mrs. Gillyflower embraced her daughter. "You have always been so very useful." She put a small revolver to Ada's head.

Elise rushed forward, but the Doctor stopped her.

"No, Mrs. Gillyflower."

"Please, Mama. No more. No more," Ada begged.

"And now, if you'll please forgive us, we must be going. It is long past Ada's bedtime." She opened a door and forced Ada out in front of her, before locking the door behind them.

Clara ran to the door.

"No, no, Clara. If we follow straight after her, she'll shoot Ada on the spot," the Doctor told her.

"She wouldn't."

"She would."

The Doctor walked over to the control panel. "Chairs are useful." He pulled the chair out of the control panel and used it to break a window.

They ran through Sweetville to get back to the rocket.

"Stop!" Ada screamed.

They ran to the top of the stairs.

"Just let her go, Mrs. Gillyflower. Let Ada go," the Doctor said.

"Secondary firing mechanism, Doctor. Mister Sweet and I are too smart for you, after all."

"Just let your daughter go, Mrs. Gillyflower."

"Monster!" Ada cried. Ada broke free and stumbled down to the platform.

"Ada!" Mrs. Gillyflower yelled.

"Shoot if you wish, Mama. It is of no matter, for you killed me a long time ago!"

The Doctor rushed forward to grab Ada, but Mrs. Gillyflower fired a shot at him.

Elise shoved him aside.

"Elise, no!"

Elise grabbed Ada and pulled her away as Mrs. Gillyflower pulled the lever, causing the rocket's engines to start.

Mrs. Gillyflower cackled. "Now, Mister Sweet, now the whole world will taste your lethal kiss!"

"I don't think so, Mrs. Gillyflower," the Doctor said. He snapped his fingers and Jenny and Vastra appeared in pilgrim clothes, holding the bottle of venom.

"Very well, then. If I can't take the world with me, you will have to do. Die, you freaks. Die! Die!" She aimed her gun at Vastra and Jenny, only to have Strax appear on the roof.

"Put down your weapon, human female."

Mrs. Gillyflower fired a shot at Strax, who fired a shot back. It sent her tumbling over the railing. She fell two stories and hit the ground.

The Doctor and Elise winced.

They all ran down to see Mister Sweet dragging itself across the floor.

"No. No. Mister Sweet, where are you going? You can't leave me now, Mister Sweet," Mrs. Gillyflower begged.

"What's it doing?" Clara asked.

"It knows she's dying. She's no longer of any use to it."

"Mister Sweet. Ada?" Mrs. Gillyflower asked.

Ada made her way down the stairs.

"Ada. Are you there?"

Ada knelt down. "I'm here, Mama."

"Forgive me, my child. Forgive me."

"Never."

"That's my girl." Mrs. Gillyflower breathed her last breath as the rocket exploded.

"What will you do with that thing?" Jenny asked, gesturing to Mister Sweet.

"Take it back to the Jurassic era, maybe. Out of harm's way," the Doctor said.

Ada tapped the floor until her stick tapped Mister Sweet. She used her stick as a bat and smashed Mister Sweet to bits.

"On the other hand..."

They made their way back to the TARDIS.

Elise lovingly patted the blue box. She'd missed her. The TARDIS did too, going off the way she hummed under Elise's fingertips.

"Right. Right, London. We were heading for London, weren't we?" the Doctor asked.

"Was there any particular reason?" Clara asked.

"We were going to pick up Elise, remember?"

"Ah, yes. Well she's here now. Shall we still go?"

"No. No. Just thought you might like it." The Doctor met Elise's eyes.

"Yeah. Maybe had enough of Victorian values for a bit." Clara opened the door and went inside.

"You're the boss."

Clara poked her head out. "Am I?"

"No. No. Get in."

Clara popped back inside and Elise and the Doctor walked back over to Ada.

"Now, Ada, I'd love to stay and help clear up the mess, but..."

"I know, dear monster. You have things to do," she told him.

"And what about you?"

"Oh, there are many things a bright young lady can do to occupy her time. It's time I stepped out of the darkness and into the light."

"Good luck, Ada. You know, I think you will be just..." He kissed her on the cheek. "Splendid!" The Doctor walked over to Madame Vastra, Jenny, and Strax.

Elise turned to Ada. "You really are remarkable, Ada. Your mother was wrong about you."

"It's very sweet of you to say that."

"Before I met the Doctor...well let's just say I didn't think anyone really cared for me and then I met him. If I can go from a scared little girl to who I am today, you can too."

The Doctor finished saying his goodbyes to the Paternoster Gang and started to head to the TARDIS.

"But Doctor. That girl, Clara. You haven't explained," Jenny said.

"No, I haven't." He walked over to the TARDIS. "Ah, look at the muck in here. Right!" He went inside.

Elise gave them all a small salute and said, "See you next time!"

A/N - I cannot wait for the 50th Anniversary Special. So many answers and so many more questions!