After the French Revolution, the new republic government is formed and an operative of this new government is sent undercover to infiltrate the inner circle of Robespierre. The agent pretends to be a rogue, like Robespierre, with the intention of finding a certain black book containing the names of friends and foes alike of the French scoundrel. This book is vital in bringing down Robespierre and his attempt to take control of France from the new government and the operative mission places him in the gravest danger, if his identity is revealed.