Retired archaeologist Judith Potts lives alone in a faded mansion in the peaceful town of Marlow, filling her time by setting crosswords for the local paper. During one of her regular wild swims in the Thames, Judith hears a gunshot coming from a neighbour’s garden and believes a brutal murder has taken place.

After leaving paradise and seeking a quieter life, Humphrey has taken a job as Detective Inspector in his fiancée Martha’s hometown. But with the high crime rate, maybe things will be louder than expected.