The famous jazzman Carlos Rivera was shot right during a concert. And it so happened that Inspector Roderick Alleyn was present among the audience at the time the crime was committed! But who was the killer? Lord Pastern-and-Baggett, who did everything to promote Carlos’s jazz band—and in return received only black ingratitude? The stern wife of the Lord, Lady Cecile, who discovered that Rivera was having an affair with her daughter, the beautiful Felicité? Or maybe some other enemy or jealous person among the many who hated the celebrated musician?