Single mom Emily Locke is building a new life with her daughter. Hoping to spend more time at home, she's put her career on hold to work part-time for her private investigator friend, Richard Cole. It's a nice balance between work and family until Emily finds out she's been working for the attorney that defended her husband's killer.

The discovery nearly destroys her friendship with Richard, but Emily resists abandoning his client, the socialite Carissa Gaston, who awaits trial for the murder of a local plastic surgeon. The threat of losing her children to a self-serving ex-husband terrifies Carissa more than the specter of a life behind bars. Sympathetic to a mother's fears and unconvinced of Carissa's guilt, Emily resolves to stick with the case despite her growing concerns about Richard and the dubious attorney who hired him.

A mysterious note leads her into a daring undercover ruse at a high brow ladies health club. Impervious to fashion trends, disinterested in beauty treatments, Emily fakes conformity with Houston's elite debutantes and trophy wives in a surreal fitness subculture where things, and people, are seldom what they seem. At this gym, 'killer workout' has a whole new meaning.