St John wrote the apocalyptic Book of Revelation over 1900 years ago in a cave on Greece's eastern Aegean island of Patmos. When a revered monk from that holy island's thousand-year-old monastery is murdered in Patmos's town square during Easter Week, Chief Inspector Andreas Kaldis is called upon to find the killer.

Andreas's impolitic search for answers brings him face-to-face with a scandal haunting the world's oldest surviving monastic community. On the pristine Aegean peninsula of Mount Athos, isolated from the rest of humanity, twenty monasteries sit protecting the secrets of Byzantium amid a way of life virtually unchanged for more than 1500 years. But today this sacred refuge harbours modern international intrigues that threaten to destroy the very heart of the Church . . . in a matter of days.