J.M. Briggs 
The Iron Gate [EPUB ebook] 

When the physical forces of multiple worlds come into conflict, magic appears. On our world certain humans are given the ability to control this energy in order to fight back the threat. In Ravenslake, home to a small university, a new generation of mages has been called forth as an ancient enemy of Earth seeks to return for slaves and control over the world.

Alex Adams now has at least some control over her magical powers, though magic lessons with Merlin and Morgana are still on the agenda. The more she learns about the war she’s now a part of, the less confident she feels. She still has feeling for Arthur Pendred despite his status as the reincarnation of the warrior mage who inspired the story of King Arthur. Complicating things are his girlfriend Jenny who is Guinevere and his best friend Lance is of course Lancelot. That story never ends well and to protect Arthur, Merlin and Morgana are ready to destroy the threat even if it costs Alex her friends. With the Sídhe still poised to attack, it is only a matter of time before an ancient betrayal destroys the fragile balance.