The first few chapters of Lost and Found are written mainly by me, whitehound, although including input from cecelle, aloe and Dyce. Thanks are especially due to cecelle for advice on the medical bits. Later chapters, in which the growing friendship between Snape and Hermione becomes a major factor, are written collaboratively between myself and Dyce, with Dyce writing the great majority of Hermione's dialogue and also some of Snape's scenes, and still with some input from cecelle and aloe. Most of the Snape/Hermione dialogue in later chapters was written like an extempore play, with whitehound doing Snape's voice and Dyce doing Hermione, and then just letting the characters talk to each other and seeing where it took us.
Missing in Action was written before the publication of The Half-Blood Prince, and the whole sequence is therefore AU. We have tried, however, to make Lost and Found compatible with the background revealed in HBP. The story follows canon closely, therefore, except that it diverges from the main or JKR time-line at the end of OotP. Fewer Death Eaters were captured following the battle at the Ministry than in JK's timeline. Lucius in particular is still free, and as a result Draco was not forced to take the Dark Mark that summer, and the incident of the Unbreakable Vow never happened.
In addition, when Dumbledore was injured by the cursed Peverell ring he called Snape to assist him immediately, instead of delaying as we are shown that he did (in Snape's memories in Deathly Hallows), so the curse has been stabilized. He has been left with a permanently maimed hand but the curse is not actually progressing.
In Missing in Action, the Daily Prophet reported that Snape had disappeared following a raid on the school, and said that this was four years after Voldemort's return, that Harry had graduated "last year" and that Snape's role as a spy had been revealed also "last year." Harry will graduate in 1998, so this would set the action in 1999. That would indeed be four years after Voldemort's return to full human (ish) life at the end of Goblet of Fire, which was in 1995, and if Harry is post-grad that explains him calling Dumbledore "Albus" in the story.
However, given all the progress Dumbledore makes with uncovering horcruxes etc. during HBP, it seems unlikely that Voldemort would still be in such a position of power by summer 1999, and also for plot-purposes I wanted to have Harry and co. still at school when Snape's fate is discovered, and it would be stretching credulity to have them all have stayed on post-grad.
So for my own purposes I'm assuming that the Daily Prophet accused Snape of being a Death Eater soon after the Ministry battle in summer 1996, when ex-Minister Fudge told one of their reporters about Snape showing him the Dark Mark. To prevent the Board of Governors from demanding Snape's resignation, Dumbledore countered this by saying publicly that Snape was his agent. This did not of itself end his career as a spy, since Voldemort has known all along that Dumbledore thinks Snape is his agent - he just thinks he's wrong. But it inflamed Bellatrix's suspicions and caused her to go digging. Snape stayed on as Potions master (since there was no reason to think he would be leaving in a year), and the raid during which he disappeared occurred in summer 1997, in place of the "Flight of the Prince" episode and a few days after he had successfully treated Albus for poisoning following the pendant-horcrux incident.
In saying that Voldemort returned four years ago, the Prophet is thinking of his return to independent if only semi-human form, which occurred some time between 1992 and 1994, and it is vaguely assuming Snape collaborated with Pettigrew in getting him back to Britain. And the Prophet is simply wrong about Harry graduating, having confused his OWLs with his NEWTs. It is not, after all, a paper known for great accuracy.
Because Draco did not take the Dark Mark in the summer between 5th and 6th years, there was no accidental poisoning of Ron, and therefore no sudden, warm reconciliation between him and Hermione. He has split from Lavender and he and Hermione are getting along OK-ish, but they aren't really dating.
