The wooden frame of the bed digs into his back, and he remembers that he is on the TARDIS. He can feel the accelerated thump of Dex's heart pounding frantically in his little chest. The burn in his muscles is nearly unbearable now, and he remembers to breathe. His sudden respirations break the silence, fast and shuddery and loud.

Dex shifts and looks up him, eyes damp and swollen, eyelashes glistening. His face is red and tear streaked, full of guilt. "I'm sorry." The words come out surprisingly steady.

The Doctor finds that he can break further. He hadn't thought it possible. He cups his palm around Dex's jawline and runs his thumb over his -her- cheekbone. He looks Dex in the eyes. "Listen to me," he says, voice rough and low. "It is not your fault. None of it was ever, ever your fault."

Dex's eyes swim with tears. He sniffs and turns away. "It is," he whispers. "I wasn't s'posed to be there."

The Doctor is silent. Dex needs to get it out, and there is nothing to do but wait.

Slowly, haltingly, Dex tells him of Mum's strange behavior, her disappearances and his suspicions. He tells him of the fire and the overheard conversation and Gran's denial. He explains how he broke into Mum's office, planning to go through her files or hack her computer for information. Finally, he tells the Doctor how he found the yellow button on Mum's desk and pressed it out of curiosity.

Dex lapses into silence. They sit like that for a long while. The Doctor watches Dex out of the corner of his eye. He is so like her, he thinks. That's exactly what she would have done. Brave, and stubborn, and loyal, and reckless, and oh, so brilliant. His hearts clinch with every breath. It hurts beyond anything he's ever known, losing her.

"I'll never see Gran or Grandad or Tony again, will I?" Dex asks softly, absently picking at the rubber of his trainers.

The Doctor opens his arms. "Come here." Dex does not hesitate; he leans into the Doctor's embrace. The Doctor rests his cheek on Dex's head. It feels good, the support.

"Can I stay with you?" Dex asks after a long silence.

The Doctor suddenly realizes that he wants this more than anything. The guilt of it nearly chokes him. He cannot keep Dex, would not survive the inevitable loss of him, will not allow himself to destroy Dex like everything else he touches. Oh, this will kill him.

"Dex," he starts, sighing heavily and bracing himself. It is going to hurt.

Dex cuts him off. "What else would you do with me?"

Before he can come up with an answer to that - there is none- Dex continues, "What's gonna happen to you?" His voice cracks and his eyes are full of concern.

Rassilon, he cannot do this. He pulls back and grips Dex's shoulders with both hands, looking him in the eye. "You and I," he says, voice low and rough and deadly serious, "are going to be very, very careful." Oh, he is tempting the universe, knows he is. Dex stares at him with luminous green eyes and nods solemnly, and the Doctor feels something cold and hard building in his hearts. Resolve. He leans his forehead on Dex's, pulling him close. "I will not lose you," he whispers fiercely. It is a threat and a prayer and a promise, redemption and absolution and a second chance. He dares the universe to try.

Dex seems to understand. "Come on," he says after a long moment. He stands and tugs on the Doctor's hand. "We need tea."

The Doctor nearly laughs. It is not perfect, might never be again, but he has Dex, and that's a start. The grief is still there, circling the edge of his consciousness, threatening to devour him as soon as his guard is down. He knows he will spend many nights in this room, consumed by it, knows he will never make peace with his past, will never overcome the guilt and regret, will always miss her, deeply and terribly and fiercely, but he will go on, and maybe, one day - if he's very, very lucky- he will be okay. He stands and allows Dex to lead him from the room.