Fly a Little Faster (смешанная)

Everyone knows when you go back in time, you shouldn't step on an ant, just in case you accidentally kill your own grandparent or something. But what happens when you go back in time and, uh, accidentally interrupt the one event that apparently made the Grumpiest Alpha in Town into a ball of mindless manpain?
Well, if Marty McFly can do it, so can Stiles Stilinski. All he has to do is get Derek and Paige to fall in love before he gets pulled back to his own time. And before he makes anything worse. That's easy as pie, right? Right?