They placed Qiang's body in a side room, just off the bridge, that seemed to act as a rest spot for the bridge crew during shifts. It was kitted out with bunks and sheets, one of which they laid over him, covering his face. Zolner and Jian spent a few minutes with him, saying their own private goodbyes, before returning to the bridge. Maddie had never really gotten to know the man, while Clara and Ashildr were the odd ones out, though they too shared a moment of silence in his memory. When all that had passed, Zolner and Maddie stepped to one side, a quiet but impassioned argument finally coming to the fore.

From what the others could make out, this was Maddie's opportunity to tell Zolner of her true goal, with an almost certain chance of the Sergeant actually listening and accepting her words. There could be no denial that Ares was to blame for Qiang's death, and the nature of the mission would have to switch now from extraction to elimination. Clara and Ashildr, however, were not privy to this conversation. Instead, they sat on a couple of crew seats near the front viewport, admiring the image of Jupiter and its moons in the distance. Again, Ashildr could see the Nerva Beacon, somewhat closer now – she reasoned that its trajectory must be bringing it somewhat near to the Tolstoy, though with the station remaining in a geosynchronous orbit it would still take a few hours to get anywhere near the ship.

"I guess... I owe you one now, huh." Clara's voice was barely a whisper, but clear enough for Ashildr to pick it up. "No idea what that gas would have done to me. But thanks. I mean it."

The older girl wasn't sure just what to say. Except, maybe, for one thing. "Nothing to owe. It makes us even."

Clara looked across to her. "Even? How? I don't see..."

"You saved me once, even if you don't remember. I don't mean the Mire tech. I... I'm not sure how much you remember from..." She paused, then continued. "The trap street. Right before you..."

Clara cast her mind back, though from her perspective it had only been a week or so. Not even that, in fact. Just a few days of relaxing in the TARDIS before coming here. Actually, it was all the more amazing that Ashildr could remember something from so long ago, what would have been billions of years to her. Why was it that the girl could remember anything to do with Clara, and the Doctor (to a lesser extent), though as she had stated herself her memory was limited with her advanced age? What was so interesting about Clara to cause those memories to remain? Still, the trap street was the key for this minor mystery. How had Clara saved Ashildr's life?

"Before you... before you came here. Before the extraction chamber. What did you tell the Doctor?"

Of course. What had her words been? "Wherever she is sending you, I know what you are capable of. Don't be a warrior." The words came easily now, she could recite them from memory.

"He made a promise to you. One he couldn't break, and he wanted to. By every god known to man and Time Lord, he wanted to, desperately." Ashildr's eyes were glistening, but still she continued on. "I spent so many years scared of his vengeance, that he'd one day forget his promise. That he'd break that rule, the one rule you made him follow."

That made Clara recall something the Doctor had told her, so long ago. Before his change, when he'd been the young and handsome man she had first met and admired. "He told me once, about a battle. It was before Trenzalore, the last time. He said something to me then, a memory from before. 'Good men don't need rules. Today...'" she paused, then continued. "'Today is not the day to find out why I have so many.'"

"He was good." Ashildr was certain of that. "He still is. And so are you. You saved my life, Clara, and I never forgot that. So... thank you."

Clara could only smile. She didn't have any words, and she didn't need any. They sat in silence once more.

A few minutes later, Maddie returned. Zolner had retreated to the navigation station further along, where she was briefly giving orders to Jian. "I think that went better than expected," the scientist reported. "She's agreed to change the mission parameters. We're going after Ares. But there's a problem."

"Let me guess," said Clara. "We're safe in here, but every other system is controlled by Ares. The moment we walk out he could do literally anything, and there's no-one left that he wants to keep alive."

"Absolutely right. It's a catch-22. He can't just beam himself away, he needs a hardware transfer to leave here - he needs us to get him off the ship. If we all die then an automated signal gets sent to HQ. They'll destroy the Tolstoy remotely, Ares included. It's not ideal though, because it doesn't purge him from the system if anything survives, and HQ still want him intact. But he can't let us reach the server room because we'll destroy him ourselves. Either way he loses. But he may just decide to go out with a bang."

At this point, they were joined by the others. A meeting was held, and ideas discussed. What nobody mentioned, though, was Ashildr. It was unclear how, but her presence seemed to have just been accepted by the soldiers. Maddie, however, was more familiar with her. Every time she spoke to the immortal, it was like they'd known each other for years already, though Ashildr was certain they had never met. One mystery had gone but another was now in its place. She'd believed Clara from the start when Clara had mentioned time travel. She was acting like an old friend, to both girls, without either understanding why. Ashildr had some very strong suspicions, but no proof, no certainty.

It didn't take long to reach a plan. The crew rest room had oxygen supplies, space suits and other equipment they could use to reach the servers once more. Filtered air to mitigate the risk of the poison gas. Ares would probably try to vent the corridors, to stop them even breathing, but in the suits they would have more than enough oxygen to complete the mission. They could deal with the known threats, but the problem was that there were too few knowns. Whatever was unknown would be the real risk. Most of the ship's systems were run from the engineering bay, currently under the AI's control, with the bridge on a separate system in case boarding parties took control of the lower decks. It would be easy to retreat back to the bridge if needed, but this would get progressively harder the further they were from the site. And they couldn't leave anyone behind, for one person to make a run for the servers. If one fell, the others would need to pick up the load. They only had one datapad available to upload the virus that would destroy Ares, and truth be told, only Maddie had the capability to use it – DNA and life-sign encoded security that was supposed to have ensured she would be kept alive by the soldiers if her previously planned betrayal was found out, but now proving more of a liability. Her survival was paramount. If she died, then the group would have no choice but to force their way off ship, or reach the TARDIS, and destroy the Tolstoy from a distance. Not the ideal solution, if any Ares-infected computer parts survived and were picked up by salvage crews.

As they prepared, Ashildr took Maddie to one side. It wasn't exactly obvious to a casual onlooker, but she managed to subtly bring them both a short distance away from the others, where it would be harder to be overheard. A quick, sly glance to Clara indicated the younger girl should listen in. "Ares... you helped create him. Am I right?"

"That's right."

"But you were the one who decided he needed to be destroyed."

Already Maddie could see the trap she was in. She'd been reluctant to talk to Clara before, about these things, trying not to give away too much information. This time, though, she couldn't ease her way out of the conversation. Ashildr was more direct, and now both she and Clara were present, involved. "I was... I was told by someone. That this... would all happen."

"One of us." Now it was out there, in the open. This wasn't the first time Maddie had met the girls. Maybe from their point of view, yes. But not from the scientist's perspective. Which meant that they would see her again, at some point. Maybe sooner, maybe later, but eventually, their paths would cross once more. But Maddie seemed relieved, to finally admit the truth. With a coy smile on her face, she looked both of them in the eye, in turn, let out a brief sigh, and whispered just one word.

"Spoilers."