By day she was Catherine the Queen. By night she was Catherine the Great.

When British Capt. Charles Edstaston arrives at the court of Catherine the Great in St. Petersburg, Russia, he is stunned by the palace's disorderly condition. The severely intoxicated Prince Potemkin concludes that the handsome Edstaston would be a suitable lover for Catherine, and he coerces the bewildered visitor into her bedchamber. Edstaston manages to escape, but he is repeatedly recaptured and delivered to the mischievous Catherine.