your resident mary macdonald expert!

So one day the three of them find Remus sat in the common room doing homework and there's a rat on the table near him. Mary casually is like "oh hey did you get a rat Remus?" None of them notice him significantly nervous as he tells them he got it during their last summer break (Lily and Mary are plotting, Marlene is wracking her brains cause she could've sworn he'd owned a rabbit)

So anyway after some deliberation the girls decide they're going to hide Remus's rat, just for a little bit. It takes a few days before they get a chance but then they see James with the rat, Lily is able to distract him long enough for Marlene and Mary to smuggle the rat up to their dormitory.

Peter actually has quite a grand time during this whole debacle, he gets treated rather well by the girls and finds that it's not as difficult to live as a rat as one might think.

James, Sirius, and Remus, on the other hand? Absolutely losing it. The first day or two they're thinking "Pete is a smart lad I'm sure he's okay." (S) "Yeah, he'll turn up." (J) and Remus is the only one who's worrying, then after day 3, teachers have started asking questions. It's only a matter of time before they get suspicious of "he's very ill professor we couldn't even get him to the hospital wing he needs to keep resting in bed"

It ends on day 4. Mary and Marlene would've kept it going, but Lily gets a bit of a guilty conscience and she returns the rat to Remus. She does however find it quite odd when he hugs her, runs over to Sirius and James, and the three of them look close to tears of joy before running up to the dorms.