Werewolf Camp

[plutot_la_vie]

Hi everyone! I'm looking for a fic where James and Sirius are sent to visit a werewolf camp that Remus is a member of by either the Order or Dumbledore, I believe under the premise of allying themselves with the enemy. I remember that Remus looks after the kids in the camp, and the Sirius and James spend the full moon with the camp as Animagus, and I'm pretty sure that the camp is Fenrir Greyback's.
Thanks so much for any help!