The Shadows Feel Like Home The Nano. In which the Pevensies trip, fall, and somehow end up in Torchwood. It's not Susan's fault she shot an alien that was trying to kill Jack Harkness.
Spell-and-grammar checked but that's about it.
And yeah, this is pretty much the sequel to the National Service series. With added 'oh shut up I may or may not have adjusted the years a bit. And Susan is working for customs and excise, rather than the vague job she had.'