Gilbert de Rideford is a Knight of the Temple of Solomon, and an old acquaintance from Crowner John's crusading days. He claims to have come into possession of a secret that could shake Christendom to its very foundations - and he desperately needs John's help to escape from the secretive order of warrior monks.

Suddenly swept into a world of religious intrigue and dangerous politics, Sir John de Wolfe finds himself undertaking a life-threatening mission to the island of Lundy - inhabited solely by notorious pirates - and uncovering the extraordinary truth behind the awful secret itself.