In 1271, the Seventh Crusade has failed. During their retreat, the troops transport the remains of King Louis IX, the Holy King, across the peninsula. A world has ended, and five young people with nothing in common set out to find the location of the Holy Shroud, stolen by traitors at the French court. Their journey will take them from the Tuscan-Emilian Apennines to Thebes, where the sacred relic is hidden.