In the Russian countryside, Rasputin heals the sick wife of an innkeeper, but seduces the innkeeper's daughter. A young man tries to kill him, but Rasputin cuts off his hand and then tries to rape the screaming daughter. People come from the inn and attack him, but he escapes to his monastery.

When he is later hauled before an Orthodox bishop for his sexual immorality and violence, the innkeeper springs to the monk's defense. Rasputin protests that he is sexually immoral because he likes to give God "sins worth forgiving" (loosely based on Rasputin's rumored connection to Khlysty, an obscure Christian sect which believed that those deliberately committing fornication, then repenting bitterly, would be closer to God). He also claims to have healing powers in his hands, and is unperturbed by the bishop's accusation that his power comes from Satan.

Rasputin heads for Saint Petersburg, where he forces his way into the home of Dr. Zargo, from where he begins his campaign to gain influence over the Tsarina. He manipulates one of the Tsarina's ladies-in-waiting, Sonia, whom he uses to satisfy his voracious sexual appetite and gain access to the Tsarina. He places her in a trance and commands her to cause an apparent accident that will injure the czar's young heir Alexei, so that Rasputin can be called to court to heal him. After this success, he hypnotizes the Tsarina to replace her existing doctor with Zargo (who has previously been struck off after a scandal).

However, Rasputin's ruthless pursuit of wealth and prestige, and increasing control over the royal household, attracts opposition. When Rasputin rejects Sonia saying that she has served her purpose, she tries to kill him. Rasputin places Sonia in a trance telling her to destroy herself.

Sonia's brother, Peter, finds Sonia dead from cutting her wrists and is so enraged by Rasputin's seduction and killing of his sister, he enlists the help of Ivan, brother of Vanessa, a beautiful handmaiden of the Tsarina who has attracted Rasputin's attention, to bring about the monk's downfall. Peter, in challenging the monk, is horribly scarred by acid thrown in his face, and suffers a lingering death.

Tricking Rasputin into thinking his sister Vanessa is interested in him, Ivan arranges a supposed meeting. However, Zargo has poisoned the wine and chocolates, which the monk starts to consume. Soon Rasputin collapses, but the poison is not enough to kill him. In the ensuing struggle between the three men, Zargo is stabbed by Rasputin and quickly dies, though not before grabbing onto Rasputin's leg and turning the battle against him. Ivan manages to throw Rasputin out of the window to his death.
Cast

    Christopher Lee as Grigori Rasputin
    Barbara Shelley as Sonia
    Richard Pasco as Dr Boris Zargo
    Francis Matthews as Ivan
    Suzan Farmer as Vanessa
    Dinsdale Landen as Peter
    Renée Asherson as the Tsarina
    Derek Francis as Innkeeper
    John Welsh as The Abbot
    Joss Ackland as The Bishop
    Robert Duncan as the Tsarevich
    Alan Tilvern as Patron
    Bryan Marshall as Vassily
    Brian Wilde as Vassily's Father