White (The Circles #3) by Ted Dekker

Thomas Hunter has only days to survive two separate realms of danger, deceit, and destruction. The fates of both worlds now rest on his unique ability to shift realities through his dreams. Thomas and The Circle must quickly decide who they can trust--both with their own lives and the fate of millions. And neither the terror of Black nor the treachery of Red can prepare Thomas for the forces aligned against The Circle in White.