"So Biv decided not to bring the Apos'alu to Gallifrey?" Jenny said. "But to imprison it?"

"Inside his TARDIS, yes," Kardeni confirmed, still working inside the console. "I don't know what happened after that. He got kind of vague. But I know he wrote that message I showed you after he returned a second time. He claimed he had proof that Rassilon was behind all of it." She jumped up and tried again, but the console didn't work. "The original design of the prison was to be a gravitational anomaly that no one could ever access." She kicked the console. "When Biv returned, he wanted to move the prison back into normal space-time, so he could prove to the Time Lords that he was right. But I guess he got interrupted before he finished."

"You mean he made one stable access point — which Lantro found," Jenny guessed. "But other little access points open up randomly and unexpectedly, causing ships to constantly crash into it."

Kardeni nodded, fiddling with some settings.

"So why's the Apos'alu after you?" Branden asked.

"Because of some stupid joke of Andrew's," Kardeni said, spinning around to face them, "that's gone terribly, horribly wrong! Now, the Apos'alu is convinced that I'm..."

With a loud "schwump" sound, the door to the outside unlocked and whirred open, revealing a horde of dead creatures on the ground and their killer — a well-armed and furious Stenman — stepping through, raising his gun. Branden screamed and collapsed as a staser bolt slammed into his chest. Jenny just barely ducked the next shot — and Kardeni leapt in between Jenny and Stenman's staser, shielding her.

"Is that supposed to be a disincentive? Having to shoot you first?" Stenman kept the staser pointed at Kardeni. "You were supposed to be next. And your boyfriend. I've had more than enough of you two conspiring behind my back!"

"I don't know what you're talking about," Kardeni said. "I told you, I haven't spoken to Andrew in two…"

"Oh, give it a rest! Edmund and I know everything," said Stenman. "Lantro clearly wants that Apos'alu weapon thing you found for himself. I had assumed that was why he poisoned you — to stop you from warning us. Of course, on my way back here, I had a rather enlightening visit to the hospital, where a pile of cash managed to get me access to your medical file. Guess what I found out about your 'poisoning'?"

"I can explain..." Kardeni said.

"What's there to explain?" Stenman advanced on her. "The vault is open. All the creatures are free. That's practically a signed confession."

Kardeni stumbled backwards — bumping into Jenny. "But I didn't release the creatures in the vault! It was..."

"The Battle TARDIS only responds to you — that's what you always say, isn't it?" Stenman snapped. "So who else could have released...?"

Kardeni screamed.

A firestorm whipped out from nowhere, wrapping itself around her as she began to disappear. She pulled something out of her pocket — a bleeping device — stared at it, stunned... and then she vanished.

"And the watch?" Yimi asked.

The Doctor perked up a bit. "Yes. That's a thing, isn't it? Never expected that. Almost enough to get one's hopes up." He quickly explained to her about the chameleon arch. Then, leaning over, whispered to Yimi, "Small question. Pretty sure the answer's no. Just have to ask. You haven't been hiding a broken fob watch with strange astral symbols on the front, right?"

Yimi shook her head. "Aren't you?"

"Me? Oh, no," the Doctor waved his hands emphatically. "No, no, no! I watched Biv die. He never left me anything to indicate he'd survived. No notes, no clues, no nothing. When Lantro brought up the watch, I thought maybe..." He trailed off, the bitter crush of disappointment washing across him. "But no. No. It was all a lie."

"You don't want to get your hopes up again," Yimi observed.

"Yes," the Doctor said. Then, "No!" Then, "Possibly." He brushed his fringe out of his eyes. "Zeera's a common name for this century. So's Beverley. Lantro hasn't told the truth yet. And Biv left me no note." The Doctor put his hand to his head. "Even that telepathic signal was a fake, put into my head by the Apos'alu." He dropped it. Stared ahead as he ran, looking sad and very, very alone.

"But maybe you're wrong," Yimi said. "You thought you were before. You told the Apos'alu that you thought Lantro's friend was Biv!"

"Of course I did — she said it was the only reason I was still alive!" the Doctor said. "I wasn't about to say, 'No, that's daft; Biv's dead and Lantro clearly made the whole thing up.' She'd have killed me on the spot." He looked down at Yimi. "You saw what she did to Lantro."

Yimi nodded. Then frowned, confused. "But why did she kill Lantro and not you?"

"Oh, well, she was keeping me alive because she thought I'd be able to find it," the Doctor explained, adjusting his bow tie. "She was keeping Lantro alive because she thought he'd already found it."

"And he hadn't."

"Nope! It was all a lie," said the Doctor. "Lantro looked the Apos'alu straight in the eye. In her currently weakened state, that's the only way she'd be able to tell if he was lying. And she said he was." The Doctor frowned, thinking a moment. "Actually, now that you mention it — that wasn't what she said. She said Lantro thought I had it. So maybe... just maybe..."

The Doctor trailed off.

Then he sighed and shook his head. "Agent Lantro. I never did work him out in the end."

Stenman stared at where Kardeni had just vanished. His jaw dropped.

Jenny leapt at him. Caught by surprise, he almost dropped the gun the moment she jumped him, so she was easily able to grab it from him, grab him by the wrist, twist him around and slam him against the wall — gun at his head.

"Right," said Jenny. "I don't know what that was all about — but my dad and Seo are still stuck inside that vault of yours. So you're going to help me get them out."

Stenman gave a bitter laugh. "Good luck retrieving them without Kardeni. She's the only one who could get the TARDIS to cooperate. None of the rest of us knew how."

Interesting...

But Jenny didn't have time to get into that right now.

"Why did you come in here?" she demanded. "Not for Kardeni. You had another reason for coming here."

Stenman said nothing.

Jenny's eyes scanned the room — and landed on an incongruous cord dangling from the ceiling. "What's upstairs?"

"Maintenance level," said Stenman. "Nothing important. This room was designed as a maintenance closet."

"And I think I've got my answer." She let him go, but kept the gun trained on him. "Upstairs. Now."

Stenman sighed, but went over to the cord and tugged at it. A hatch opened up in the ceiling, and a gust of wind sucked both Jenny and Stenman up into the upper level, sealing the hatch behind them.

"And... just as I thought," Jenny said, landing gracefully on her feet — even as Stenman wound up flat on his face. "The air conditioning units." She tucked the gun away, and began to inspect them. "I'm guessing you brought some stuff we can use to make sleeping gas, or something else to knock everyone else out down below?"

"Why should I tell you anything?" Stenman demanded.

Jenny sighed. "Because, Mr. Stenman, I think your Apos'alu already got loose — and is trying to find a way to unlock the rest of the swarm from its prison. Kardeni's disappearance is proof enough of that."

"What? Why?" Stenman shook his head. "How do you know all this? Did Zeera tell you?"

Jenny sighed. She thought she could reason out what was going on. The only question now was whether Stenman would actually believe her.