The Bone Season by Samantha Shannon

A major event - the first book a seven-part series of dizzying imagination.

Welcome to Scion: No Safer Place. It is the year 2059. Several major world cities are under the control of a security force called Scion. Paige Mahoney works in the criminal underworld of Scion London, part of a secret cell known as the Seven Seals. The work she does is unusual: scouting for information by breaking into others’ minds. Paige is a dreamwalker, a rare kind of clairvoyant, and in this world, the voyants commit treason simply by breathing.

But when Paige is captured and arrested, she encounters a power more sinister even than Scion. The voyant prison is a separate city—Oxford, erased from the map two centuries ago and now controlled by a powerful, otherworldly race. These creatures, the Rephaim, value the voyants highly—as soldiers in their army.

Paige is assigned to a Rephaite keeper, Warden, who will be in charge of her care and training. He is her master. Her natural enemy. But if she wants to regain her freedom, Paige will have to learn something of his mind and his own mysterious motives.