Broken Things by Barbara Elsborg

An ancient book of faerie magic. A renegade who will stop at nothing to possess it. And the two boys who stand in his way.

When fifteen-year-old Tar, part vampire, part something else, helps his father break into a remote house, he doesn’t care about the book his father is looking for. What he does care about is the little locked-up faerie kid. Merrick is alone, vulnerable and deaf.
The break in goes wrong, but Tar refuses to leave the eight-year-old even though it means facing his father’s fury. Events spiral from bad, to worse, to out of control: the book disappears, and Tar and Merrick are wrenched apart.
The boys grow into men, one living in the light and one in darkness, yet neither has forgotten the other. As powerful forces rise, the search for the missing book gains momentum, and Tar and Merrick’s paths collide once more.
Merrick is the key to the missing book and Tar is faced with a near impossible task: to keep the man he cares for safe, and do everything he can to stop the book and its secrets from falling into the wrong hands. And maybe, just maybe, save the world as we know it.