奥赛罗（谢尔盖·邦达尔丘克 Sergei Bondarchuk 饰）是骁勇善战的大将军，元老的女儿苔丝狄蒙娜（伊琳娜·斯科布采娃 Irina Skobtseva 饰）爱上了他，但因为奥赛罗是一名黑人，所以两人的婚事遭到了元老的反对。不愿意就此放弃这段感情的两人决定私定终身，这个秘密被一直嫉妒奥赛罗的旗官伊阿古（安德烈·波波夫 Andrei Popov 饰）给暗中偷听到了，于是伊阿古决定破坏这段姻缘。哪知道伊阿古的捣乱反而促成了这段婚事。
伊阿古并没有善罢甘休，奥戴罗和苔丝狄蒙娜结婚之后，伊阿古通过伪造定情信物的手段开始挑拨这对夫妻之间的感情。占有欲极强的奥赛罗很快就走进了伊阿古设置的圈套之中。

A portrait of the era of "Red Terror" during the civil war that followed the Bolshevik revolution, The Seventh Companion offers a character study in General Adamov (Andrei Popov), a law professor in the tsarist army, who is incarcerated by the Bolshevik secret police along with many other members of the bourgeoisie. Finally released into the new world of the Soviet Union, the resigned officer finds that he has lost everything from his old life except a mantel clock that he carries through the night from place to place, until he ends up back where he started.