The Daupin, heir to the French throne, is kidnapped. The boy is held in an orphanage where those in charge have been instructed to brainwash him in order that he should forget his true identity.
Naturally, Percy and his friends are on the case and are determined to rescue him but their plans are foiled by a masked man breaking into the orphanage and taking the boy before they have a chance.
There are many excellent twists and turns in this episode and, as usual, some magnificent acting, most particularly by Richard E. Grant as Percy and Ronan Vilbert as a very nervous Robespierre who knows that his own end cannot be far away.
Magnificent, as usual.