London, 1660. The monarchy had only just been restored after the “hostile whirlwinds” of the revolution. Cromwell's corpse was dug out of the grave, hanged, and then beheaded. Isaac Inchbold, the owner of the Rare Book second-hand bookshop, receives a strange order: to find the Hermetic treatise “The Labyrinth of the World,” which was not included in the corpus of works of Hermes Trismegistus, translated by Marsilio Ficino into Latin for the Florentine ruler Cosimo de’ Medici, and exists in a single copy. A second-hand book search turns into a detective investigation, unraveling a tangle of intrigue, the threads of which lead to the storming of Prague by the troops of the Catholic League in 1620 and to the mysterious South American expedition of Sir Walter Raleigh.