A French-language version, translated and adapted by Charlotte and Marie-Louise Desroyses, was also produced under the title La Capture du Mouron Rouge.

It is 1794 and Paris, "despite the horrors that had stained her walls - has remained a city of pleasure, and the knife of the guillotine did scarce descend more often than did the drop-scenes on the stage."

The plot begins when Sir Percy, the Scarlet Pimpernel, reluctantly agrees to take Armand St. Just, brother of his wife, Marguerite, with him to France as part of a plan to rescue the young Dauphin.

Learning of her peril and in the throes of passion, Armand fails to trust Sir Percy who has told him that he will rescue Jeanne, and forgets his promise to his leader.

Chauvelin insists that Percy is to be deprived of sleep in the hope that he will be weakened and disclose where young Capet, the uncrowned King of France, is being held following his rescue.