As a penalty for fighting fellow classmates days before graduating from West Point, J.E.B. Stuart, George Armstrong Custer and four friends are assigned to the 2nd Cavalry, stationed at Fort Leavenworth. While there they aid in the capture and execution of the abolitionist, John Brown following the Battle of Harper's Ferry.
Vladimir Dubrouvsky, a lieutenant in the Russian army, catches the eye of Czarina Catherine II. He spurns her advances and flees, and she puts out a warrant for his arrest, dead or alive. Vladimir learns that his father's lands have been taken by the evil Kyrilla Troekouroff, and his father dies. He dons a black mask, and becomes the outlaw The Black Eagle. He enters the Troekouroff household disguised as a French instructor for Kyrilla's daughter Mascha. He is after vengeance, but instead falls in love with Mascha.
Dr. Henry Jekyll believes that there are two distinct sides to men - a good and an evil side. He believes that by separating the two, man can become liberated. He succeeds in his experiments with chemicals to accomplish this and transforms into Hyde to commit horrendous crimes. When he discontinues use of the drug, it is already too late.