Remus was having a horrible time sleeping. He'd been tossing and turning for a couple of hours, but slumber was nowhere nearer to him. He knew Sirius wasn't in the room; he'd never heard him come in, and knew Sirius hadn't been in before he arrived himself. That bothered Remus, though he knew it shouldn't have. It wasn't his place to know where Sirius was going at all times of the day or night.
After a couple of hours with no success trying to sleep, Remus sat up in his bed and put his feet in his slippers. If sleep wasn't going to come to him, then he decided he was going to make good use of his time. He picked up a couple of his school books and started to make his way down to the Common Room. He didn't want to wake James or Peter, so he decided to do some studying by himself. What he found when he reached the communal space shocked him. Sirius was huddled in a ball on the couch, and looked like he was having a fit of sorts.
Maybe he should've ignored him -- Merlin knew after all the things Sirius had said to him and to their friends he probably deserved it. But that wasn't Remus. He couldn't ignore Sirius no matter how much he should have or even wanted to. "Sirius," he said softly, and moved over to sit next to him on the couch. Remus set his books aside and placed a hand on his shoulder. "What's wrong?"