In Sweden in the 18th century, two opposing sides want to get hold of a book: "The Chronicle of the Black Monks", where an evil society, Codex Dei, is revealed. The Codex Dei with officer Anckarström, also disguised as a priest, tries to get back the chronicle from the good side of the Queen, family Streck and a loyal officer (Per Ragnar). Meanwhile Russian troops are harassing the Swedish countryside.