It’s summer on Gotland and an international group of archaeology students are excavating an ancient Viking site. The camaraderie and holiday spirits of the group are shattered when one of their members, a Dutch student named Martina, disappears. When her naked body is found hanging from a tree, with what appear to be ritualistic markings on her skin, Inspector Knutas can’t ignore the echoes from Gotland’s Viking past. Martina has been killed according to the old Viking ritual of the three-fold death – a ritual that guarantees more deaths will follow.