"I'll take the responsibility," the Doctor immediately volunteered. "She already knows I absorbed the energy of the Time Vortex. It's near enough to my fault, what happened to you, in any case. She doesn't need to know that she absorbed the energy first. I'm not entirely certain how much she remembers, or will remember, in this case. I have a feeling she knows she did something, but back on the Crucible, when you were shot, she had no idea you could come back."
They hadn't spent much time explaining things back then. There'd been the Daleks to worry about, then the Earth, then getting everyone home. The Doctor had been more concerned with seeing everyone settled before Donna's mind began to feel the strain of supporting a Time Lord consciousness than with being certain everyone was on the same page.
"It wasn't her fault, not really. As brilliant as she is ... she's still human. She couldn't have properly controlled the energy, not really. I even had trouble, and I'm a Time Lord."
He listened, then, as Jack went on to explain how things were with his team, frowning at first, then drawing his eyebrows together in mingled confusion and skepticism as Jack told him they were all three together. "Typical fifty-first century human male," he finally said, gently teasing. "But a family ... that's good. That's brilliant." His tone was subdued, wistful. It had been so long since he'd had a family of his own.