This is what I think is going to happen in Silverborn by Jessica Townsend!

WARNING: This book is part 2 of a series. Please read Xelqua Rising first before reading this description as it contains spoilers. Finally settling into his new life as a Watcher, Xelqua has made a critical error. Accidentally going into a world with another Watcher named Miesall, he must find his way back to the Watcher's residence, the Downside Up before anything else can go wrong. If only it proved to be that simple...

The school year has started again, and already everything has changed. Friendships have been made and broken, trust has been built and destroyed. Only the truest of friends can survive a year like this. But can the emperors?