FIC: Derek/Stiles: Derek is betrayed by {season 3 spoiler}
The Alphas, Deucalion in particular, seem to know an awful lot about the Hales. In addition, there appears to be a connection between Deucalion and the Argents. So, what if he also knows about what Kate did to Derek/Derek's family? What if Deucalion attempts to use that same M.O. on Derek now? In other words, what if Miss Blake is in league with the Alphas? And it’s her job to further isolate Derek from his pack? Maybe Scott becomes preoccupied with Isaac and Stiles is left to his own devices and notices that something is ~off? How this becomes Derek/Stiles is up to the author.