It was happening tonight. On these nights, Remus hung out in the library, pretending that he was doing homework. The others called him a nerd for risking getting caught for the sake of studying, but they called him a nerd anyway, so he didn't care too much. They'd always be gone before...it happened. And once everyone was gone, he'd sneak outside to the place Dumbledore had shown him, out in the school grounds.
He'd reach the Whomping Willow, and normally find a rock to throw at the knot on its trunk, before scurrying past the branches. Once he was safely past them and in the tunnel, Remus shed his clothes, so that he would have something to wear back to the castle in the morning. He couldn't remember how many times he'd ruin clothes at home because of his condition.
It was all Fenrir Greyback's fault he had to live like this. Once a month, his body would go through the painful transformation into a beast, and all sense of who he is would vanish. Remus's parents had tried any number of cures, but nothing had been found to work against lycanthropy yet. It was part of the reason Remus studied so hard: he was hoping that one day, he could find a cure for this disease.
Every month Remus would hope that maybe, just maybe, this time it would be different. That maybe it had miraculously cured itself. But no, it came back every time, every bit as painful as the last time.
As Remus climbed the last incline into the Shrieking Shack, he felt the familiar twinge of his bones restructuring themselves into those of a wolf. Remus hurried along, quickly climbing through the trapdoor in the floor and closing it. When he finally finished changing, he was always too dumb to figure out that there was a door there to escape through. On top of that, Dumbledore had strengthened the walls and doors to the shack with various charms, making escape nearly impossible.
Remus howled in pain as he felt his spine reconfigure itself, and fingers shrink down into paws with long, sharp claws. He'd gone through all this a hundred times before, but it never seemed to get any easier. Remus had tried to resist the change in the past, and had even had some success. However, being half-transformed had been excruciating, so he started just letting the thing consume him.
Remus's vision began to fade, and almost on cue, thoughts of rage and destruction started infecting his mind, before he blacked out completely...
Remus woke up in the middle of a trashed room, the leg of a table snapped in two held in each of his hands. Remus didn't want to stay long, nor could he afford to. His friends would miss him soon, so Remus quickly ran back to the trapdoor, yanked it open, and jogged back through the tunnel to where he'd left his clothes.
Before leaving the tunnel, Remus always had to check to see if anyone was around. Sometimes there were teachers, who were all aware of his condition, but it was students he was really concerned about. If any of them ever found out about...no, Remus couldn't think about that. Just get back to the castle, and play it off as getting an early breakfast. That tended to work.
Remus peered out of the tunnel, and saw no-one. He then checked in a strategically placed mirror, hidden under a rock so that no-one would see it unless they knew it was there, in case someone was behind the tree. 'No-one,' thought Remus. 'Great, I'm outta here.'
Remus climbed out of the hole, and ran straight for the castle, avoiding the Whomping Willow's branches as he went. There was no-one around, which was a good thing as he ran across the grounds and back to the castle. Remus snuck in through the Entrance Hall, and into the Great Hall where breakfast was just getting served. 'No-one is any the wiser,' he thought, sitting down and grabbing some bacon.
James got back into the dormitory, took off his invisibility cloak, and as quietly as possible, roused Peter and Sirius. "Guys, I know where Remus goes every month," he said.
"Oh? Where then?" asked Sirius.
"There's a hole at the bottom of the Whomping Willow," said James. "He goes through there after he hits a knot on its trunk."
"So where's the hole go?" asked Peter.
"I'm not sure," admitted James. "I couldn't get close enough to the tree to hit the knot, then Mrs. Lewis appeared."
"Filch's bloody cat," muttered Sirius. "So basically, you know he sneaks off the school grounds, but not where?"
"That's the gist of it, yes," admitted James.
"Well, all we have to do is..." started Sirius.
"Will you guys shut up?" said Richard, another boy in their dorm. "Why are you even up this early on a Sunday?"
"...we'll continue this later," said James, crawling into bed after having been out all night.