"Can't you just, you know?" Clara asked.

"What?" the Doctor asked.

"Fly the TARDIS into the parallel universe?"

"Ah, it's not a parallel universe. It's a pocket universe. Plus, it is collapsing. I mean, the TARDIS could get in there all right, but entropy would bleed her power sources, you see? Trap her there until the entire universe decayed back into the quantum foam. Which would take about three minutes, give or take, you know."

Elise patted Clara on the shoulder. "In other words, no."

The Doctor finished what he was doing and they went back to the music room where the Doctor rigged the crystal up.

"What is that?" Clara asked, reaching for it.

The Doctor slapped her hand. "A subset of the Eye of Harmony."

"I don't..."

"Of course you don't. Be weird if you did. I barely do myself." He turned to Emma. "Right. You, sit down. All the way from Metebelis Three." He put a headset with a blue gem on Emma's head.

"What does it do?" she asked.

"It amplifies your natural abilities like a microphone, or a pooper scooper."

"What exactly is this arrangement?" Palmer asked.

"A psycho-chronograph."

"Forgive me, but isn't it all a bit well, make do and mend?"

Clara helped the Doctor into a parachute harness.

"Non-psychic technology won't work where I'm going. Listen, all I need to do is dive into another dimension, find the time traveler, help her escape the monster. Get home before the entire dimension collapses and Bob's your uncle."

"Doctor, will it hurt?" Emma asked.

"No. Well, yes. Probably. A bit. Well, quite a lot. I don't know. It might be agony. To be perfectly honest, I'll be interested to find out."

Emma looked at Palmer, who nodded. "I'm talking to the lost soul that abides in this place. I'm speaking to Hila Tacorian."

All the clocks in the room started to spin backward.

The Doctor attached his harness to a thick rope as the black disc from earlier appeared.

Wind filled the room.

"See? The Witch of the Well! It's a wormhole!" the Doctor yelled over the noise.

"A reality well! A door to the echo universe. Ready?"

"Ready!" Emma yelled.

"Geronimo." The Doctor jumped into the wormhole.

Elise looked at the wormhole and made a decision. She grabbed the rope and let it pull her in.

"Elise! Doctor!" Clara yelled.

Elise hit the ground next to her father.

He pulled off the harness and helped her up. "What are you doing here!" he yelled.

"You and me, remember? If you go, I'm going with you."

The Doctor groaned. "Oh, you are loyal to a fault! We don't have time for this." He grabbed her hand and they started running. "Hila? Hila! Hila Tacorian!" the Doctor called.

Sticks and leaves around them snapped.

"One, two, three." The Doctor spun around as Hila cried, "Help me! Help!"

She finally ran into them.

"Hila Tacorian, I presume," the Doctor said.

"Who are you?" she asked.

"Collapsing universe. You and me, dead, two minutes. No time complete sentences. Abandon planet."

"Wait. There's something in the mist."

"Then run. Run!"

"Doctor! Elise! Doctor! Come home! Elise, Doctor, come home!" Emma's voice called.

They ran back the way they came, but were stopped by the edge of the pocket universe.

"Not that way, which means, er, probably..." The Doctor turned around and started running the other way.

"What's wrong?" Hila asked.

"You know that exit I mentioned?"

"Yes?"

"I seem to have misplaced it."

There was rustling in the woods all around them.

"Doctor!" Emma's voice called.

It sounded far away.

"This way," the Doctor told them.

"Doctor! Elise! Come home! Elise, Doctor, we're here."

Something was visible through the trees and the mist.

"Whoa," the Doctor said.

"What's that?" Hila asked.

"An echo house, in an echo universe. Clever psychic. That is just top-notch."

"Doctor! Doctor!" Emma yelled.

They ran inside the echo house and the Doctor locked the doors.

The creature outside scratched on the doors.

"It's looking for a way in," the Doctor said.

They made their way to the music room, where the wormhole now was.

"Grab the rope. Give it three tugs, quick as you like," the Doctor told Hila.

She put on the harness. "What about you?"

"We'll be next." The creature banged on the door.

"Oh, that's what that noise was. Lovely."

Just as Elise and the Doctor were about to grab the rope, the wormhole disappeared.

The next thing they knew, they were standing in the woods again and they could hear the creature growling.

"Oh dear," the Doctor said, "Oh dear. Where are you?"

Elise clutched onto the Doctor in fear. Elise and the Doctor ran around the woods until the echo house reappeared and the wormhole reopened.

"Doctor! Doctor, we're here. Come home," Emma called.

"Emma?" the Doctor asked.

A snarl came from behind them.

"What do you want? To frighten me, I suppose, eh? Because that's what you do. You hide. You're the bogeyman under the bed, seeking whom you may devour. You want me to be afraid. Then well done. I am the Doctor, and I am afraid."

Elise was scared as well, but she wasn't shaking.

"Doctor, hurry!" Emma yelled.

"So why am I still here, huh? Why not just eat us? Ha? Come on. Because you still need me."

The creature came out from behind a tree.

"Yeah, you need us to piggyback you across. To which I say, come on then, big boy, chase us."

Elise and the Doctor took off running.

It eventually caught up with them and knocked the Doctor down. The TARDIS came spinning towards them, knocking the creature off the Doctor.

The Doctor and Elise grabbed onto the TARDIS and they soon materialized in the music room.

Elise collapsed on her back.

"Elise!" the Doctor yelled, dropping to knees to examine her.

He smoothed her red hair back from her face, but she wasn't hurt or crying.

She was smiling.

Emma hugged Hila and the Doctor joined in. "Where will you go?" Emma asked her.

"He can't take me home. History says I went missing."

"But he can change history."

"No, no, no, I can't, actually. There are fixed points in time, you see..." the Doctor said.

Clara popped in. "Hi."

"What?"

Clara grabbed the Doctor's arm, pulling him away so the two women could have a moment.

"I knew you were there. I could feel you," Hila told Emma.

"I know."

"Have we...?"

"We can't have. You haven't even been born yet."

The Doctor popped back in. "No, you can't have met but she can be your great, great, great, great, great granddaughter."

Major Palmer walked up.

"Yours too, of course. But you guessed that already, didn't you." He saw the shocked looks on both Emma's and Palmer's faces. "Oh. Apparently not."

"The paradoxes..." Palmer said.

"Resolve themselves, by and large. That's why the psychic link was so powerful. Blood calling to blood, out of time. Not everything ends. Not love. Not always." The Doctor started for the TARDIS and Palmer ran after him.

Emma, Palmer, and himself spoke amongst themselves before the Doctor smacked himself in the forehead.

"Oh, I'm so slow! I am slow. I'm notorious for it. That's always been my problem. But, but I get there in the end. Oh yes."

"Doctor?" Clara asked.

"How do sharks make babies?" Clara gave him a confused look.

"Carefully?"

"No, no, no. Happily!"

"Sharks don't actually smile. They're just, well, they've got lots and lots of teeth. They're quite eaty."

"Exactly. But birds do it, bees do it, even educated fleas do it. Every lonely monster needs a companion." He ran towards the castle, where something moved upstairs near the window.

"There's two of them?" Clara asked.

"It's the oldest story in the universe, this one or any other. Boy and girl fall in love, get separated by events. War, politics, accidents in time. She's thrown out of the hex, or he's thrown into it." The Doctor threw his arm around Clara's shoulder.

"Since then they've been yearning for each other across time and space, across dimensions. This isn't a ghost story, it's a love story!" He smiled at Clara and then quickly removed his arm from her shoulder. "Sorry." He ran back to Emma, Hila, and Palmer.

Elise and the Doctor were alone in the TARDIS after dropping everyone else.

"I know how you feel about her," Elise said.

"About who?" the Doctor asked.

Elise playfully rolled her eyes. "You know who. Clara."

The Doctor nervously played with a control on the console. "What?"

"I've been with you for over 400 years. I know you. You love her."

"Elise..."

Elise put her hand on his arm. "It's okay if you can't admit it. But I can see it in the way you look at her and how you treat her. I know you won't say it out loud because you clearly lost someone you were in love with and I'm willing to guess it's the one you won't talk about. The one you wish more than anything you could forget."

"Elise...earlier..."

"Yeah?"

The Doctor sighed. "Nevermind." He pulled out a box. "Major Palmer wanted you to have this."

Elise opened the box and saw supplies to develop pictures. She kissed him on the cheek and disappeared down the TARDIS corridor.

He wanted to tell her so badly. But how could he? How could he tell her that her own love story would mimic that of the creatures?

Two lovers separated by time and space.