The Casket of Maria Medici (Russian: Ларец Марии Медичи, romanized: Larets Marii Medichi) is a 1980 Soviet historical action film directed by Rudolf Fruntov [ru].

[4] In medieval France in 1244, crusaders lay siege to the fortress of Montségur, leading to the demise of the Albigensians—followers of a doctrine considered heretical by the Catholic Church.

As authorities investigate Savigny’s disappearance, they initially suspect murder, only to discover that he is actually Vsevolod Yurievich Svinin, the son of White émigrés.

During World War II, Svinin betrayed his allegiance and collaborated with the Nazis in an attempt to uncover the Albigensians' secret, even going so far as to force a young girl, Madeleine, and her mother, descendants of Montségur, to witness a brutal execution.

Captain Vladimir Lyusin, with the aid of historian and expert Yuri Berezovsky, must delve into both recent crimes and this ancient mystery rooted in the 13th century to uncover the secrets of the old chest and the motives behind the unfolding events.