The novel follows San Francisco Detective Lindsay Boxer as her life is upended. Fifteen months prior, her life seemed perfect with her husband, Joe, and their baby daughter. However, she discovers that everything she knew about Joe was a lie, and his betrayal cuts deep.

As Lindsay grapples with this personal turmoil, a wave of mysterious heart attacks strikes seemingly unrelated victims across San Francisco, leading her to investigate if there is a sinister plot at work. Simultaneously, a dangerous bomber whom Lindsay and Joe had previously captured is on trial, and his defense raises damning questions about the initial investigation, threatening Lindsay’s career and potentially making her the one on trial.