Sumeria, 5.5 thousand years ago. There is a fierce struggle for power in the state of Lagash. The Brotherhood of the Black Snake also has plans to take over Sumeria with the help of witchcraft, but to do this it is necessary to find the missing link - the Amulet, and destroy its Guardian. The first adviser to the ruler of Lagash, the most likely future ruler, defeated the army of robbers, capturing its leader and an unknown Scandinavian warrior. But events take an unexpected turn, and, escaping, the former enemies go together into vast and dangerous swamps.