Aldo Branch is a homicide detective in Houston, and also an amateur musician who loves playing viola in string quartets. He is called to a Houston park where the members of the Kyoto Quartet have been found murdered and their Stradivarius instruments stolen. Branch and his partner, Chat (for Chatahoochee) Jackson, begin by interviewing the Houston elites who had attended the post-concert party at the home of billionaire oilman Clint Mattingly. Celia Hargrove, an insurance investigator, soon joins them. Branch is attracted to her, though he is still obsessed by a pianist named Allegra, who has married a possible suspect. Branch's own quartet consists of a physician, an engineer, and a physicist, who sometimes give him information helpful to his case. Also involved is a right-wing group interested in something other than the Strads.