Retired archaeologist Judith Potts’s peaceful evening in Marlow is shattered when she hears a gunshot coming from her neighbor’s garden and believes that a brutal murder has taken place. With the local police – led by newly promoted DS Tanika Malik – reluctant to believe her story, Judith starts her own investigation, enlisting the help of unfulfilled vicar’s wife Becks Starling. Judith digs into the alibi of the arrogant owner of the local auction house, but her suspicions ultimately hits a dead end. An ominous warning message leaves Judith even more determined to catch the killer, and local dog-walker and empty nester Suzie Harris makes a terrible discovery that personally involves her in the investigation.