The ship carrying the devout to Jerusalem has run into rough waters, in this third outing for Sister Pelagia. Onboard is Manuila, controversial leader of the Foundlings, a sect that worships him as the Messiah. But soon the polarizing leader is no longer a passenger or a prophet but a corpse, beaten to death by someone almost supernaturally strong. But not everything is as it seems, and soon the clumsy, bespectacled, yet surprisingly astute nun finds her investigation taking her to the most dangerous areas of the Middle East and Russia. She emerges with not just the culprit in the case but also a clue to the earth's greatest secret.