Mackellan Kirby, professor of Ancient Religious Studies, with some ongoing connection to the British SAS, is enjoying retirement in Ireland, when he discovers an anomaly in the Dead Sea Scroll he has been entrusted with translating. Always ready to solve any mystery, he enlists the aid of his American niece and nephew. Their search takes them to the cathedral of Santiago de Compostela, in northern Spain, the goal of thousands of pilgrims every year. But their holiday jaunt immediately turns deadly when other factions become interested in their search. The artifact they recover, in the cellars of the cathedral, brings together writings from the first century A.D. about a charismatic leader who escaped from Judaea with his wife Mary; the story of the eleventh century bishop entrusted with the construction of the cathedral; and the truth of the Conspiracy of St. James--a cover-up of a secret so significant that its exposure could rock the modern Christian church to its knees. If only Kirby and his young relatives live long enough.

Mysterious murders make the pilgrims on the Way of St James shudder from the Pyrenees to Santiago de Compostela. By chance, one of the pilgrims, the German chief detective Raschke from Mecklenburg-Vorpommern, witnessed an act. At first, the encounter seems random. Then, however, a series of murders begins, which takes place parallel to the pilgrimage of the police officer. Attacks are also committed on Raschke, who is apparently to be eliminated as an annoying witness. For the Spanish police, the German becomes a decoy who should lead them to the perpetrators.

Reprint of the original, first published in 1865.