Why are sheep in the remote Egyptian village of Mehenopolis cutting their own throats? That's the mystery Emperor Justinian inexplicably sends John, his Lord Chamberlain, to Egypt to solve. Mehenopolis is a pilgrim destination, thanks to its ancient shrine to a snake deity.

Among the characters John encounters are a pretentious local landowner battling a self-styled magician for control of the lucrative shrine, an exiled heretical cleric, an itinerant beekeeper, and a disgraced charioteer. Will John uncover what is really happening to these sheep? Are these slayings somehow linked to the murder charge of which John has frantically tried to clear himself?