TW: Glad you enjoyed it. Between Torchwood and the Time Agency, Jack is probably more used to this kind of stuff than The Doctor at this point.
Jane led the group into the dining room, where the TARDIS had once again prepared a meal for them. They all sat down; absently beginning to fill their plates as they tried to process everything they had learned. It was silent for a few moments before Jack spoke up.
"It was a Siren, wasn't it?" Jack said knowingly and everyone looked up at him in confusion.
"What?" Mickey asked in confusion.
"Yesterday, Jane told Donna that something got out of a hole punched in the fabric of reality and that it started manipulating The Doctor's life from that moment on. It was Siren, wasn't it?" Jack asked as he looked at Jane, whose expression was carefully crafted into a calm mask.
"What makes you say that?" Jane asked calmly.
"The way you reacted to the Siren. You seem to hate them even more than you hate Weeping Angels. It's the only thing that makes sense. So am I right?" Jack asked as they all looked at Jane, waiting to see if she would fold.
For a long moment, Jane was silent, seeming to weigh her options. Finally, she spoke with a tired sigh.
"There's no word for it in the English language. Closest translation is 'Space Siren'. It's believed to be a distant cousin to the Sirens of myth on Earth," Jane finally admitted.
"So Jack's right, it was a Siren," Martha said, in a bit of shock as Jane nodded.
"Sort of. Space Sirens didn't charm their victims the way the Sirens here on earth did. They used the power of their words, sort of like The Master. They didn't have the same hypnotic power as The Master, but they could influence creatures less evolved than them, bend their will to their own, make them do things they wouldn't normally do," Jane explained.
"And that's what happened to The Doctor?" Wilf asked in surprise and Jane nodded.
"Sort of. Getting out of the tear in reality wasn't easy, it almost killed it. Eventually, it took refuge inside the body of a normal human, drawing on her life force while it recovered. It was able to control her from time to time, until it gained enough power to completely take over," Jane explained as they listened with growing horror. "Dad encountered the Space Siren when it was just starting to gain control of her and, well, it was able to influence him. And like I told Donna, by the time he put it all together, it was too late."
"Time Lords are one of the most evolved species in the universe. It shouldn't have been able to influence him," Jack said in bewilderment.
"Under normal circumstances, you'd be right. But when it found Dad, he wasn't his usual self," Jane paused as they looked at her in confusion. "He was in pain, had cut himself off from everyone else. He'd even renounced being The Doctor. He was at a low point in his life, probably the lowest since the Time War. And that let The Siren influence him."
"And that's what you're trying to prevent," Donna noted and Jane nodded.
"If I can. Anything is better than the last few years," Jane sighed heavily.
"You said he was in pain. The Doctor, he lost someone?" Jack asked and Jane looked at him with an expression that made the temperature seem to drop several degrees.
"He lost everything," Jane said softly, thinking once more of Manhattan. "It left him more broken than I'd ever seen him. Even under the influence of the Siren, I'd see him with this look in his eyes, like he was all hollowed out inside. I should have known something was wrong, but I was too happy to have him back."
For a long moment, it was silent, everyone trying to process what they had just heard. It was hard for them to imagine The Doctor being controlled in such a way but if Jane was right, that's exactly what happened.
"So this Space Siren, what exactly did it want?" Martha asked, still not getting it.
"Revenge. The Doctor had encountered it a long time ago, before the Time War. He locked it away in a Time Lock, until it got out. So when it got out, it wanted to make him suffer," Jane said grimly.
"They always do," Jack said grimly and Jane shook her head.
"Not like this. It wanted to make the universe burn around him so it could show him that it was his fault. And that's exactly what it did," Jane said darkly.
"So the Siren made Boss do something and it led to the end of the universe?" Mickey asked and Jane nodded.
"Yes. And that's what I need your help to stop. I need you to stop the Siren," Jane explained.
"Whatever you need us to do, just tell us," Donna said eagerly and Jane smiled tightly.
"Not yet. There's still a lot more you need to see, to understand. And then, once you do, you may not be so eager to do as I say," Jane said ominously.
The past viewers exchanged bewildered glances, wondering what could be so bad.
But Jane was finally being honest with them about what happened. So for now, they would trust her and go along, continuing to watch the recording. And, hopefully, they would be able to save their friend and the universe itself.
So yeah, that's basically what happened to The Doctor in this universe. There are still a lot of things that won't make sense about it until later, but I do hope my explanation about the Space Siren made sense.