“Hmm? Oh, just curiosity. That’s all. Wondering about the way the universe works. So many things aren’t what I think…I mean, think about it. Daleks. How many times do I have to destroy them? And yet they keep coming back. Cybers too. Everything cycles around. Donna…well, Donna was a bit of a bigger thing than coincidence, the way we kept finding each other. And crossing universes. Keep doing it, despite the improbability.” He pauses, considering. “Has there been anything, weird readings, welll, weirder than normal I suppose, in regards to the Rift? Only there’s something more going on, there has to be. Things just keep coming back.” His rambling seems half directed at Jack and half at the air around him.
"Oh, it's only short-term. It helps her. Being young, and me being not a full Time Lord..."