I am sorry to bother you with a fic search but I am looking for months now for a very old fic that must be somewhere in Moonshadow (I think) but where… I don’t know the author nor the title.
The story starts when Severus comes back from a DE meeting in a very bad shape. It is snowing and very cold. Somehow Lupin manages to save him from the cold (I think he felt in the lake…) and to brink him back to Hogward. Moody is playing a bad role in the story because he doesn’t like werewolves and he (or somebody else) leaves Remus to die outside.
I remember also that Severus disappears at one point and that Remus is using a “crystal” or something like that that only a werewolf can use to spy on Voldemort. Something wrong happened and Remus end up in an immaterial form in the head of a wolf…
There is also an invocation by Voldemort of a Demon who finally helps Remus and Severus.