the_debt_of_time

They woke the following morning, and Mia turned away to allow Sirius and James
to cover up a naked and sleeping Remus—who miraculously lacked any wounds at all, save
for a few bruises from the actual transformation.
"Want to tell us what that was all about this morning?" Sirius asked, his arms folded
over his chest.
"Instincts," Mia replied quietly, "I guess I'm not used to controlling them in
Animagus form."
"That's understandable I guess." James shrugged, running his hand through his
already messy black hair. "But I still think you owe Peter an apology."
Mia inhaled sharply and looked at her brother like he had just asked her to kiss a
dementor. "I will not apologise for acting on instinct. It's not my fault."
"Mia," Remus moaned from the corner. "Please... I don't want anyone to fight."
She turned bitterly away from them all and then slowly brought her gaze up to Peter,
who looked at her with watery eyes. It was hard now not to see him for what he really was:
selfish. He stole things from the trolley, abandoned his friends in times of crisis, even spied
on people—which she had caught him doing twice already this year. And while Sirius and
James often got carried away when they fought with Slytherins—Snape especially since he
had started being a bit of a berk to Lily in public—Peter had been thrown into detention
twice for getting caught bullying younger students.
Now that she was an Animagus, Mia could see it all. See Scabbers the rat with his
missing toe that he lost while framing Sirius. Sirius who had thought Remus was the spy
when all along it had been Peter. Peter who betrayed his friends, rather than die for them
as they would have done for him. Peter who got her brother killed. Peter who made Harry
an orphan.
"I'm sorry, Peter," she said through clenched teeth.
James, Sirius, and Remus all smiled in relief at her words.
Peter stared ahead at her looking as terrified as he should have been.