An opal necklace lost in the Venetian lagoon brings together a Countess, a rich and careless young nobleman who adores her, and Damer, an English physiologist with great ambition and no scruple. When the young man falls ill, Damer holds both the serum that could save him and the toxin that will make his death certain, and follows the logic of the laboratory. Ouida wrote it in the 1890s, when the new bacteriology was a public excitement, and it is one of the coldest of her late stories; the others in the volume keep to her Italian settings. Sixty plates of Venetian lagoon light and shadow, from Guardi to Munch, keep the city itself present throughout the volume.
