Ninth House - Leigh Bardugo

(Alex Stern book 1) 

Galaxy 'Alex' Stern is the most unlikely member of Yale's freshman class. A dropout and the sole survivor of a horrific, unsolved crime, Alex was hoping for a fresh start. But a free ride to one of the world's most prestigious universities was bound to come with a catch.

Alex has been tasked with monitoring the mysterious activities of Yale's secret societies - well-known haunts of the rich and powerful. Now there's a dead girl on campus and Alex seems to be the only person who won't accept the neat answer the police and campus administration have come up with for her murder.

Because Alex knows the secret societies are far more sinister and extraordinary than anyone ever imagined. They tamper with forbidden magic. They raise the dead. And sometimes they prey on the living . . .