In a late-night showdown, Detective Lindsay Boxer has to make an instantaneous decision: in self-defence she fires her weapon - and sets off a chain of events that leaves a police force disgraced, a city divided and a family destroyed. Now everything she's worked for her entire life hinges on the decision of twelve jurors. To escape the media circus, Lindsay retreats to the picturesque town of Half Moon Bay.

Soon after, a string of grisly murders punches through the community. There are no witnesses; there is no pattern. But a key detail reminds Lindsay of an unsolved murder she worked on years ago.

As summer comes into full swing, Lindsay and her friends in the Women's Murder Club battle for her life on two fronts: in court and against a ruthless killer.