No matter how strong security for students in Hogwarts was. For their staff was pretty sloppy. That or they thought adult won't sneak outside the castle walls, and that was exactly what Sebastien did. Although he knew he was allowed to go out as long as he want until he's on his workspace during his shift, he didn't wanted to go looking for someone who will open a gate for him at 3AM. Well he guessed someone would actually do that, maybe they would called him a freak, or cursed him, but opened the doors? He doubted that. That's the main reason he used secret passage under assault willow. They showed that passage to him when he returned to Hogwarts as a werewolf that should be a place he can use during the full moon, but he saw it as a way he can sneak all the way down to Hogsmeade.
It was still unusual to walk down the halls of Hogwarts, especially at night, and not being punished for that. He never thought he'll see this place, again, and if someone would tell him he'll willingly apply for a job here he would tell that person is crazy, and yet he did that, too. He didn't apply for the job because he suddenly started to like children or had an inexplicable need to be at Hogwarts again. During his schooling he couldn't wait for the day when he will graduate from the school and leave the castle forever. This ex-Slytherin applied for a job just because the books. He couldn't find a cure for lycanthropy in any library he went so far, and he hoped this time he'll be luckier, that he'll find it. This was the largest library he could think of, and when he saw that the place of librarian was free he applied for the job and got it.
So far his his search gave no results although he spent every free moment searching, he missed out the start of term feast, whereas he wasn't a professor he didn't need to be there, although they said it would be desirable he decided to pass it and spent that day in the library, sorting the books and reading some of them. Sebastien found many irrelevant facts about werewolves, but not a word for how to stop being a werewolf. He was sure it was written somewhere, he was just looking in the wrong direction, choosing wrong books. Healers found cures for many diseases so far, why would they failed in finding a cure for lycanthropy then?
Since he was bitten, before three months, he couldn't sleep well. When he hasn't had nightmares, then he had insomnia, in neither of the cases he couldn't sleep so he choose walking like today. When he realised it would be another sleepless night he he got dressed and slipped out of the castle. Bastien was walking aimlessly at Hogsmeade until darkness did not flinch before dawn and while shops aren't slowly started to open their doors for customers. He waited for The Hog's Head Inn to open and then came in, ordering a tea and sitting down at the table in the corner. It was early, he was sure that none of the students has not yet awakened and he had a plenty of time before he supposed to open the doors of the library.