I've just had the absolute privilege of beta-reading an absolutely enthralling four-chapter fic by
tardis_stowaway. It's Jack and Doctor-centric, and called Mercy of the Fallen. Imagine a post-456 Jack stumbling on an immediately-post Time War Nine. Yeah. About as angsty and heart-wrenching as you think, but also laden with so many beautiful and even humorous moments. Very true to character, as well, for both of them.
tardis_stowaway also creates a very realistic, gritty setting for her story, with alien planets and races, natural disasters and crises from the horrific to the mundane. Her aliens are distinctively alien, but also very naturally so - I never felt that I was getting banged over the head with ''this character is alien' reminders, yet I never forgot either.
It's a gripping story with some lovely yet heartwrenching hurt/comfort, and it should be coming to an LJ near you very soon - don't miss it!