Remus' eyes bugged a bit at the slap to the back, but he quickly composed himself and straightened out his jumper. Secretly, he hoped that Sirius' departure was just a quick trip down to the kitchens to find something sweet. Deep down, he knew it wasn't going to be that simple, but he still had to hold onto that hope.
He nodded to James, and caught the Map. He wasn't as excited about the whole thing, rather, he was very anxious about it. But he slipped beneath the cloak next to James. "Ready," he said, though it was only half true. He wanted to help Sirius, to find out what it was that was happening to him, but he was also very afraid to know the truth.