The Jackal by JR Ward

The location of the glymera’s notorious prison camp was lost after the raids. When a freak accident provides Nyx clues to where her sister may still be doing time, she becomes determined to find the secret subterranean labyrinth. Embarking on a journey under the earth, she learns a terrible truth—and meets a male who changes everything forever. The Jackal has been in the camp for so long he cannot recall anything of the freedom he once knew. Trapped by circumstances out of his control, he helps Nyx because he cannot help himself. After she discovers what happ…. Read more.