During the Carnevale in Venice, American Urbino Macintyre and his British friend Contessa da Capo-Zendrini, seen first in Death in a Serene City , investigate the fatal stabbing of English photographer Val Gibbon. When the nuns of the pensione where the dead man stayed ask Urbino to look into the murder, he learns that a rival photographer was jealous of Gibbon's commission to shoot the restoration work being done by Josef Lubonski. Urbino also discovers Gibbon was blackmailing Lubonski and that the victim's fiancee had nearly married Tony Vico, stepson of the Contessa's old friend Bernice Pillow, before she met Gibbon. Tony and Bernice, Urbino knows, are in Venice for the festivities. The carnival atmosphere pervades this entrancing story, rich in history and flavor, as the mystery leads up to the Contessa's masquerade ball on Shrove Tuesday.