Hopefully, it's something that Jack will gradually get to grips with the more time they spend together - at least, the more time they actually spent talking rather than fucking each other's brains out. He's made quite a lot of progress towards understanding
It takes a moment for him to get the significance of London, but then he gets it, given that they're talking about deaths, and his eyes widen. "Where you were turned?" he asks, his heartbeat picking up as he remembers the tiny snippets of it he saw in Spike's video that time.
((OOC: You know, I was going to say let's fade out but then you brought up London... *g* Though it might make sense to fade anyway and move on to something more current?))