Set in medieval Italy, Pär Lagerkvist’s novel evokes the sinister plots and deeds of Niccolò Machiavelli’s prince, who was based on Cesare Borgia. The title character is the prince’s trusted aide and henchman, Piccolino, who has dwarfism. Piccolino’s extreme loyalty encourages his complicity in nefarious attacks on the prince’s enemies, including murder. But because the narcissistic prince cannot ever trust anyone nor be satisfied that they are acting in his best interests, he later rejects his servant; blaming Piccolino for all his problems, the prince imprisons him. The reader is left to wonder if Piccolino will ever be released and if he deserves liberty.

The prince’s arch-enemy is Lodovico Montanza. The courtly setting includes an artist painting a portrait of Princess Teodora, the prince’s wife; this artist, Bernardo, and the portrait are reputedly modeled on Leonardo da Vinci and the Mona Lisa. Both the prince and his wife are having affairs. The prince keeps a courtesan, Flametta, as his mistress, while his wife’s lover is a poet, Ricardo. The prince and princess have one daughter, Angelica. As might be expected, she falls in love with Lodovico’s son, Giovanni. The plot involves her father’s efforts not only to separate them, but to punish Giovanni for seducing his virtuous child.

The prince apparently can do nothing half way. To eliminate his enemies, he pretends to negotiate a peace and stages a celebratory banquet, where he poisons Montanza and others in attendance; Piccolino goes beyond assisting him in this gruesome task—he adds the prince’s lover to the victims. The full measure of the prince’s pathology is encapsulated in his “solution” to the problem of the young people’s romance. Learning from Piccolino that Giovanni is with Angelica, the prince rushes into her room and cuts off the young man’s head right before her eyes. Mother and daughter are now desolate without their lovers; her heart broken, Angelica kills herself, while her mother wastes away in her grief but actually dies of an illness. Within all this mayhem, the prince fixates on Piccolino’s role, confining him indefinitely to a dungeon. Convinced nonetheless that he is indispensable, the dwarf expects his incarceration to be temporary.