Stiles was always too curious, too smart for his own good. Always getting into things he shouldn't, spying on people, listening to grownup conversations. The good thing was he wasn't a terribly sneaky child, so his parents always knew when he was up to something. And Stiles was often up to something. 

When they were in high school Stiles' best friend since childhood Scott was bitten by a werewolf, which in turn made him a werewolf. Stiles figured it out first, because he usually did, but Scott didn't believe him--not until he had no choice. It set their lives on a path of all matter of supernatural mayhem, which slowly pulled in the people around them. 

Werewolves, kanimas, banshees, druids--Stiles became well-versed in all kinds of supernatural lore. He didn't have powers like Scott, but he could be the guy in the chair, so to speak, and make sure they made it out of every mess alive. But then Stiles was possessed by an evil fox spirit, and he was both the one who needed to be stopped, and the one who needed to be saved. He thought it couldn't get any worse after that.

He was an idiot. It could always get worse.