Fic rec!
Even the Damned by dameruth is exactly the Doctor-Jack conversation I wanted to see in the aftermath of CoE. Spoilers galore, of course. DameRuth writes one of the best Jacks I've read, and this story is no exception to her general awesomeness. Plus, it gives a really good explanation as to why the Doctor seemed to sit this apocalypse out. Go, read, love.