In the late 1980s, a Russian general dispatches a team to locate a skull with mystical abilities hidden in the forests of the Netherlands, once owned by a medieval Frisian king. Upon its discovery, a renowned archaeologist becomes possessed by the skull, transforming into the devoted prophet of the king. A few years on, this prophet, now the head of a violent cult that includes his alluring girlfriend and relatives, commits murder and torture in the name of the ‘Almighty King Sigurd’.