A series of thefts (some comic, some sinister) puzzles Athens early in 329 BC. Stephanos has become publicly betrothed to Smikrenes' daughter in the autumn of 330, and the couple wed in Gamelion. Meanwhile, Aristotle has settled down into a sexual relationship with the slave Herpyllis. Stephanos is getting his life in order and he tries to establish his political position as an Athenian by giving a dinner party. However, the happiness of his marriage is hampered by some vexations lawsuits: one from a neighbour of his in-laws in the Hymettos property, another from the father of the girl he was once supposed to marry. Connection with Smikrenes, whose land his own child or male children will inherit, causes Stephanos to take more interest in Eleusis. The series of thefts seem to have some connection with a little shop that makes statuettes of Demeter and Kore. Stephanos and Philomela decide to become initiates of Demeter and Aristotle is persuaded to join them.

Their connection with the Mysteries allows them the chance to observe some phenomena that don't add up. In the end they are able to pin some important thefts and a murder to personages closely connected with the Mysteries. The climax comes in September 329 BC, during the celebration of the Mysteries at Eleusis.