In the fifth Charlotte Diamond mystery, the retired FBI investigator and her significant other, glamorous senior movie star Brenda Brandon (aka Boynton), return from a murder- and gem-theft-punctuated Christmas cruise down the Rhine River to confusion and catastrophe in their usually quiet retirement village of Hopewell on the Choptank in Maryland. The wooded lot next door to Brenda's historical mansion, a lot that Brenda thought she owned, is being bulldozed by a New York construction firm for a mystery development. All of the homes and land from Charlotte's own riverside cottage to the end of their road are being leveled as well, including Charlotte's neighbors' house, and she has no idea where their dog sitter may have gone with their beloved dogs, Rocket and Sam.

The two women and their previously sleepy riverside village are propelled into a hotbed of confusion, with disappearances and murder aplenty. Only Charlotte's experience and skills from her previous life in the FBI and the appearance of an old flame Charlotte has been trying to avoid because of mixed feelings enable them to start unraveling the mystery of what is happening with spymaster Win Engleton's property.