At the height of the French Revolution in 1793, a mysterious Pimpernel continues to embarrass Robespierre and the head of secret police, Citizen Chauvelin, by rescuing aristocrats from under the authorities' noses. Chauvelin travels to England to uncover the man's identity, and meets his former lover, a French actress, at a lavish ball.

The Pimpernel is called upon to track down Helene, the daughter of the Marquis de Rochambeau. However, Chauvelin is also looking for her, and so is Gabrielle Damiens, the head of the local revolutionary regime. Sooner or later, their paths are bound to cross.

The Dauphin is being held prisoner by the Republicans. When he is captured by a masked intruder, Robespierre orders Chauvelin to find the boy before news gets out.