He'd seen the scar, of course, the darkish rosebud of discolored skin, there at the juncture of neck and left shoulder. That was nothing new. In the disarray of robes, stripping and toweling down after a particularly rainy autumn Quidditch practice, they'd all seen quite a bit of each other. Sirius had been wildly curious then, openly staring. But Remus had averted his eyes, with that Remus half-smile, and pulled on his pajamas, covering the sharp half-moon scar with a carefully upturned collar. And though the four of them had stayed up half the night talking, Sirius had gone to bed without asking. It had taken him nearly half a year to get the other boy to laugh out loud; he wasn't going to risk another semester of Remus' silence over some silly scar.

Some awfully fascinating scar.

He saw it again when Remus had to borrow one of Peter's shirts after the Potions incident in their second year. (James' favorite sneakers were never the same.) They had teased him about it, the loaned shirt cut too broadly for his slender shoulders, too long in the sleeves. Remus, unperturbed, had rolled up his cuffs and ignored them. But when he turned his head, Sirius could see the tiniest hint of scar tissue-- just a peek, there, curving down across his collarbone, where anyone could see it, really, not as if he was looking for it... was it just his imagination, or did it looked a little lighter, this time, the scar half a shade paler than the flesh around it?-- before Remus' head came back around and he pinned Sirius with a curious stare. James had interrupted, seeking assistance with his Divination homework, saying Peter was no help. Remus, muttering something about not helping him cheat, smiled mildly, and turned away again.

Sirius had almost forgotten about both incidents, until class that day.

Defense Against the Dark Arts had always been Remus' favorite subject, and normally his grades ran circles around the rest of them. Even James couldn't match his marks when it came to Dark Arts essays. But in their third year, after the crochety endearing old Professor Starling had retired and keen-eyed Professor Kestrel had come to take her place, something changed. Certainly, Professor Kestrel wasn't the nicest teacher they'd had, and he managed to step on more than a few student's toes. But, rather than quietly standing up for someone unpopular, which was Remus' usual attitude, he had closed like a book. He stopped speaking in class, even to answer questions that, just last year, he had ribbed the others for not knowing, saying they were practically common sense. Sirius and Peter both aced a test, and Remus refused to show them his score. When the classroom was barely chilly, Remus sat and shivered in his grey turtleneck, looking even more withdrawn than usual.

And he had voluntarily skipped a class.

Not even visiting his sick mother, no, they were used to that. Remus Lupin had sat in his chair in the Gryffindor common room and absently told them to go on ahead, he had some reading to catch up on. Had his hand been shaking, just a little, as he shoved his hair out of his eyes? Sirius had noted, with no little suspicion, that the book in Remus' lap appeared to be upside down.

It was the next Tuesday, at their next Defense Against the Dark Arts class, when Sirius remembered the scar. Professor Kestrel was rubbing his hands together, looking pointy-faced and maliciously happy with his own lecture, saying something about rearranging the curriculum so that no one would miss today's very special lesson.

And Remus had gone white in his chair, his right hand straying, unconsciously, to lay at his neck.

Over the scar.

It was a casual enough motion, his quill still in his left hand; he looked as if he could be just about to take notes. But for the whole class, he barely breathed, staring too carefully at the open Encyclopaedia Animalia on the professor's desk, one small muscle twitching on the back of his right hand.

Sirius knew this, because for the whole class he watched only Remus, held in some sort of horrible fascination. Had he looked up to the front of the classroom, he might have noticed that Professor Kestrel was watching both of them, as well, with sparks of malevolence in his sharp eyes.

"Beasts, absolute monsters. To be disposed of, at all costs. Do I make myself clear?"

When the bell sounded, Remus fled, without speaking to any of them, looking sick. Sirius, mystified, hurried to pack his books and follow--

"Well, young Mr. Black," Professor Kestrel beamed, clapping a hand over Sirius' shoulder, preventing him from rushing after his friend. "What have you learned here today, hm?"

Sirius narrowed his eyes. Slowly, he looked from the empty doorway, to the lunar chart illustrations on the blackboard, and back at his Professor.

"I think you will write an excellent paper on werewolves, my boy," he clutched at Sirius' arm, supreme satisfaction in his oily voice. "You show great promise."

Stars and planets were all rearranging themselves in his head, making him dizzy. Involuntarily he jerked his arm away, not even giving a second thought to the star marks he was throwing out the window.

How on earth have I been so bloody dense?

Sirius' lip curled in a snarl, and he spat, "I've learned that you are an insufferable prick." He didn't stay long enough to hear himself given detention, careening down the hallways to find Remus, hoping he could catch up to him.