Dr. Sheila Tao is a professor of psychology. An expert in human behaviour. And when she began an affair with sexy, charming graduate student Ethan Wolfe, she knew she was playing with fire. Consumed by lust when they were together, desolate and depressed when they weren't, she realizes the three-month fling with her teaching assistant has to end. After all, she's engaged to a kind and loving investment banker who adores her, and her life is about to change for the better. But when she attempts to cut the affair dead in its tracks, Ethan Wolfe won't let her walk away.

Ethan has plans for Sheila, plans that involve posting a sex tape that would surely get her fired and destroy her prestigious career. Plans to make her pay for rejecting him. And as she attempts to counter his every threatening move without her colleagues or her fiancé discovering her most intimate secrets, a shattering crime rocks Puget Sound State University: a female student, a star athlete, is found stabbed to death. Someone is raising the stakes of violence, sex and blackmail...and before she knows it, Sheila is caught in a terrifying cat-and-mouse game with the lover she couldn't resist — who is now the monster who won't let her go.