In the barn, Remus curled up to wait and as the moon rose, he spasmed, bones shifting and cracking until he could lie down again, now a wolf.
The night, all in all, wasn't terribly bad. When he transformed back in the morning, he was understandably sore and tired and rather stuffed-up, but he'd felt worse. Much worse.
Once he was sure he was steady enough for a bit of travel, he made his way stiffly to the fireplace and Floo-ed home.
He emerged in the master bedroom, coughing ash and stumbling towards the bed.