Yimi jumped at the name. "Abozalu?"

Lantro looked askance at them. "What do you three know about the Apos'alu?"

The Doctor turned to Lantro and Yimi. "What do I know? What do you two know?"

"Abozalu is a god," Yimi said, "who fell to this planet long ago, and became trapped inside. Seo and I were going to find him. She thought he was someone called 'the Master'."

"The Master?" The Doctor sighed, face in his hands. "Oh, Seo, Seo! No wonder she ran. All this — because of a mistake!"

"The Apos'alu is not a Time Lord," said Mutajar. "It was born on Galia-3. Rassilon wanted it."

"Rassilon?" Yimi ruffled her feathers. "Who is...?"

"Another false god," the Doctor cut in, quickly. He turned to Lantro. "And you? What do you know? How do you know, for that matter?"

Lantro didn't say anything.

"Isn't it obvious?" Mutajar fumed. "He knows because he has Kardeni's watch! He has to! It wasn't in his office! In Stenman or Hoyer's offices! In her office! Or even on her person." She grabbed him by the collar and shook him. "Where is it? Give it to me!"

The Doctor caught a glint of something behind Lantro's back. "Wait!" He ran behind Lantro, grabbing him by the vortex manipulator. "He fixed it. Well, partially. Not enough to get him out of the vault, but enough to send some kind of signal to the Main Complex. A retrieval signal, no doubt." He buzzed the vortex manipulator with his sonic screwdriver, and it fell into a million pieces. "There. That's better."

For the first time, Lantro really did start struggling against his bonds. "Look, Doctor, she's crazy! I don't know what she's talking about!"

"Oh, I think you do," said the Doctor, stepping beside Mutajar. "Every time I got suspicious, you dropped Zeera's name. First with the Time War. Then with the Ouribiu. When I didn't take the bait, you dropped that carefully tailored fob watch description right into my lap. The perfect Time Lord distraction." He put his hand on Mutajar's shoulder, and she dropped him reluctantly. "So how about you tell us the truth?"

Lantro said nothing.

"No one's coming to save you," the Doctor warned. "And Biv's going to keep asking you until you give her an answer." He flashed a grin at Mutajar. "So!" Turned back to Lantro. "Where did you hide Zeera Kardeni's fob watch?"

For a long while, Lantro remained silent.

Then, finally, he sighed.

"She doesn't have one," Lantro muttered, looking away. "R&D is backlogged with weapons we can't figure out. Stenman and Hoyer wanted me to find a way to get Time War survivors here. I made it up as a lure to reel you in."

"You made it up," the Doctor deadpanned.

"Hey, I don't like this any more than you do," Lantro insisted. "But — think about it a second, Doctor. When I was trying to get information out of you, I didn't care about a watch. I wanted to know what 'minefield' you were talking about. What that blue poison did. What a Magenta Dragon was. Details about that weapon that grounded TARDISes."

The Doctor frowned. That was true.

"I only brought up the watch when you started losing interest," said Lantro, "to keep you hooked." He sighed. "Zeera Beverley Stenner. You can look up her birth records. She's full-blood human. Always has been."

"But you knew about the watch!" Mutajar insisted. "You described it exactly!"

"Back when we were in college, Zeera was obsessed with studying about Time Lords," said Lantro. "She used to drone on and on and on about it. You couldn't shut her up. Used to drag Craig and me to guest lectures and stuff, too. I heard about the chameleon arch by chance. Got suspicious. Started looking into it."

"And stole her fob watch," Mutajar accused.

"And found nothing," Lantro corrected. "Zeera's parents were professors specializing in Gallifreyan Lanterns. Zeera loved their research. Taught herself the language. I looked into her background. Everything made sense. No holes. No problems." He stared pointedly at the Doctor and Mutajar. "She is human."

"Liar!" Mutajar shouted.

"Oh, I'm the liar now?" Lantro turned to the Doctor. "You know, Doctor, I think there was a kernel of truth in Mutajar's story. See — I found the chameleon arch room inside this TARDIS. The chameleon arch was kind of a wreck. More so now. But back then, it still worked just enough that I could see the previous error logs. There was an attempted transfer of a non-Gallifreyan entity. Mutajar was right."

Mutajar gave a proud smile.

"But you see, it got stopped mid-way through," said Lantro. "And that got me thinking — Faye Mutajar. Daughter of Phil Mutajar — a famous Anti-Plate Cracker back before I was born. Faye was just five when the whole family disappeared. No one knew where." He glanced over at the Doctor. "I could hazard a guess. How about you?"

The Doctor grabbed Yimi by the arm and spun on his heels. "Run!" he shouted at her.

Mutajar threw up her hand. "Oh no, you don't!"

The landscape shifted around the Doctor and Yimi, grass turning to stone, walls folding out from nowhere, the sky suddenly shielded by a dripping cement ceiling. The Doctor yelped as he smacked into the far wall of a small dungeon — with bars across the windows.

"Oh." The Doctor looked around. Grimaced. "I didn't think she'd be able to do that."

"I've learned a lot from watching the humans dissect and reprogram and distort my prison," said Mutajar as she appeared at the other end, carrying a still-tied-up Lantro. She spat at him, then threw him against the far wall of the prison, where he smacked with a loud 'oomph.'

Neither the Doctor nor Yimi untied him.

"You're not as sharp as you used to be, Doctor," Mutajar observed, aiming Lantro's gun at him. "I'm disappointed."

"Have to admit, your fake Time Lord telepathic signal really threw me off." The Doctor pulled Yimi behind him, protectively, then raised up his hands in surrender. "Still, I can't help but notice that despite that shiny new human body you've possessed and taken over, you're still stuck here."

"Your prison," Mutajar gritted through her teeth, "still doesn't believe I'm human."

Yimi peaked out from behind the Doctor's back. "Who...?"

The Doctor shoved her back behind him. "Nobody! Don't worry about it!"

"Oh, let the savage see her god," said Lantro, finally managing to snag the vine on a sharp rock poking out of the wall. "Throw the dog a bone, Doctor." He broke free from his bonds and stretched out, arching his back.

"Abozalu?" Yimi stepped away from the Doctor, her jaw falling open, staring. "But you're...!"

The Doctor firmly shoved her back behind him. To Mutajar, "Why are we still alive?"

"Why have you been keeping us alive?" Lantro corrected, crossing his arms. "I've lived through falls today that should have broken my neck twenty times over."

Mutajar stepped forwards, keeping her gun trained on them. "Bivazeer."

"It wasn't an affair!" Kardeni insisted, snatching her hand away. "It was once!" She paused. "Well, twice." She paused again. "Well, maybe more than twice — but it wasn't an affair!"

"Thing is, Stenman and Hoyer were already suspicious of Lantro," Jenny said, still standing in front of the light. It blinked off. "So when you wound up in the hospital, they assumed he'd done it to stop you from telling them what he was really..."

Kardeni shoved Jenny out of the way and jabbed at the vault retrieval controls.

Nothing happened.

"It couldn't have lost the signal," Kardeni said, frantically trying again. And again. And again! "How could it have...?"

Jenny got up from where she'd fallen on the ground. She could guess who'd discovered and disabled the signal. "At a guess, Dad's figured out Lantro's on the wrong side — and wants to keep him there."

Kardeni spun back around, suddenly furious. "The vault was originally designed as a prison for the Apos'alu!" she shouted. "We managed to unlock the top few layers — but they've all gone deep, deep inside it. Without that signal, there's no way to get any of them out. They'll be trapped there forever!"

"You know, at the moment, I'm kind of okay with that," Branden said, coming over. "In fact, if there was a way to push you inside, too — I'd trap you in there with them."

Jenny held out a hand for Branden to stop.

She looked into Zeera's eyes.

"That's why you first started telling me all of this, isn't it?" Jenny said. "Because of the Apos'alu. You're afraid of it."

Zeera cringed. Then pushed past Jenny and began to work at the controls again — trying desperately to piece them together to get some part of them functional. "I have to find another way."

Jenny walked over, leaning against the console. "What is the Apos'alu really, Zeera? What did that message actually say?"

Kardeni paused.

Hesitated.