Diagoras, Tramachus's tutor at the academy, distraught with grief at the death of his pupil, asks Heracles Pontor, known as the Decipherer of Enigmas, to look into the last days of the youth's life. Heracles, intrigued by the state of the corpse, agrees: his investigations lead him into a dark world of bloody ritual, where ancient myths come to life, hidden beneath the civilised surface of Athens.