Sierra Johansson struggles to make her dysfunctional marriage to Connor work despite his cheating and reneging on a promise to start a family. When she realizes she's at a breaking point, she takes control of her life and secretly gets pregnant via artificial insemination using Byron's, a married long-term friend, sperm. She and her best friend show up at her husband's mistress' place while the lovers are in the middle of the act, and she snaps. Not long after that Sierra divorces her husband.
Distrust of men and single-parenting responsibilities of raising her son, Aubrey, challenge Sierra for a couple of lonely years. That's until she runs into Byron, who she hasn't seen since she told him she had conceived. Connor sees Sierra and Byron together and realizes the unmistakable similarities in Byron and Aubrey. It triggers his Narcissistic Personality Disorder and he goes into a rage. He then embarks upon a terrifying path of revenge. Will she be able to protect her and her son's sanity from her ex-husband's insanity?