Shadow Maker: Morrighan House Witches Book One

Physics major Dieter Lindemann is perfectly content living in a world where the Shadows he sees and hears are nothing but figments of his imagination. But when one attacks him, he's forced to confront the fact that the Shadows are not only real, but dangerous.

Though Necromancer Alistair Cudmore offers to help him, Dieter quickly realizes that what he and Alistair want are two very different things, and it's difference that could cost him his life. Controlling and possessive, Alistair pushes him further and further into blood magic, dragging him down into a world he never wanted any part in. As the spirits and Alistair grow more and more violent, Dieter must break away from his mentor and learn to control the Shadows on his own before they destroy him. Only, Alistair isn't about to let him go without a fight.