England, 1923: The Honourable Daisy Dalrymple attends a performance of Verdi's Requiem with Detective Chief Inspector Alec Fletcher of Scotland Yard. The tickets were a gift from Muriel Westlea, Daisy's neighbor and the sister of Bettina Westlea, who will be singing the mezzo role. What should be a pleasant afternoon is disrupted when, during the performance, Bettina falls dead on stage-poisoned with cyanide. While it's quickly determined that Bettina's on-stage prop glass of liqueur was laced with the deadly poison, discovering the person responsible will not be an easy task. Bettina was neither well liked nor well behaved, and many of her colleagues, associates, and even her family had good reason to want her dead. Daisy, determined to help DCI Fletcher whether he wants help or not, decides to do some investigating on her own. But with so many suspects and so few clues, the murderer may well go free...