This is the 9th book in the Alex Trotter mystery series. Alex has misgivings about escorting eight members of a family on a so-called "reunion" cruise down the Rhone River from Lyon to Arles in the late fall. Older sister Audrey's gift of the trip to younger sister Phyllis and her husband Darren disguises the fact that Audrey cheated Phyllis out of their mother's multi-million dollar estate, claiming that she was entitled to the fortune for allowing their mother to live with her and her husband Wayne for the last three years of her life. Paying their own way are two cousins and their spouses, who have not spent much time with the two sisters since they were kids, spending summers in their grandparents' cottage on the lake. By coincidence, on the cruise, they meet up with Lara, a friend at the lake, whose brother, Danny, drowned the last summer they were all together. In reminiscing about their vacations together, questions reemerge about the drowning, centering on Audrey, who appears to know more about it. A shocking drowning death on the cruise gives rise to many more questions Arlie and Alex will have to answer.