Reign of Terror (reissued as The Black Book) is a 1949 American film noir directed by Anthony Mann and starring Robert Cummings, Richard Basehart and Arlene Dahl. The film is set during the French Revolution. Plotters seek to bring down Maximilien Robespierre and end his bloodthirsty Reign of Terror.

Plot
Already the most powerful man in France, Maximilien Robespierre (Richard Basehart) wants to become the nation’s Dictator. He summons François Barras (Richard Hart), the only man who can nominate him before the National Convention. Barras refuses to do so and goes into hiding.

Meanwhile, patriot Charles D’Aubigny (Robert Cummings) secretly kills and impersonates Duval (Charles Gordon), the bloodstained prosecutor of Strasbourg, who had been summoned to Paris by Robespierre for some unknown purpose (which Robespierre’s enemies want very much to ascertain). Neither Robespierre nor Fouché (Arnold Moss), the chief of his secret police, have met Duval before, so the substitution goes undetected. Robespierre informs D’Aubigny that his black book, containing the names of those he intends to denounce and have executed, has been stolen. Robespierre’s numerous foes are kept in check by not knowing whether their names are on the list or not. If they were to learn for certain that they are on the list, they would band together against him. He gives D’Aubigny authority over everyone in France, save himself, and 24 hours to retrieve the book.

D’Aubigny meets Barras (Richard Hart) through his sole contact, Madelon (Arlene Dahl), whom D’Aubigny once loved. However, he was followed, and Barras is arrested by the police, led by Saint-Just. D’Aubigny finds himself in an uncomfortable position, but manages to allay both sides’ suspicions that he has betrayed them.

He goes to visit Barras in prison, and informs him that three of his best men have been murdered. Strangely, their rooms have not been ransacked in search of the book, leading D’Aubigny to surmise that it was never stolen in the first place, and that Robespierre is using the alleged theft to distract his foes. Saint-Just, still suspicious, sends for Duval’s wife to identify her husband. Madelon pretends to be Madame Duval and extricates her former lover while the real Madame Duval is waiting at the gate.

Before news of his impersonation spreads, D’Aubigny returns to Robespierre’s private office—located in the back rooms of a bakery—to look for the book. There he encounters the opportunistic Fouché, who seems willing to sell out his master. When D’Aubigny finds the book, however, Fouché tries to stab him. D’Aubigny strangles him into unconsciousness and escapes. He and Madelon hide out at the farmhouse of fellow conspirators, Pierre and Marie Blanchard. (The Blanchards are either under arrest in Paris or already dead at the hands of St. Just’s Sergeant (Charles McGraw). St. Just goes to the Blanchard’s farm and gets no help from Grandma (Beulah Bondi). He tries to charm one of their three young children, but loses his audience when he impatiently kicks a kitten. Meanwhile, D’Aubigny and Madelon are hiding on the property because they must retrieve the book, which is on the cot where St. Just is sleeping. With help from the children, they get the book and flee on horseback. A nighttime chase ensues. D’Aubigny gets away, but Madelon is caught, taken back to Paris, and tortured by the Sergeant. She refuses to talk. An hour before the Convention meets, Fouché appears and tells Robespierre he knows a better way. He takes an earring from Madelon.

The Convention is assembled and about to convene. Fouché shows up and shows the earring to D’Aubigny. Without the book, many more will die, Dissolve to the Convention. Fouché tips his hat to Robespierre, but Barras sees book being passed from hand to hand among the delegates while Robespierre denounces Barras in an eloquent speech. Meanwhile, D’Aubigny searches Robespierre’s office and the Sergeant takes her to a hidden room. Robespierre concludes his speech and is shocked to find himself denounced and pursued by the mob. He is followed to his office and nearly brings them to heel with his golden words, but Fouché tells a man “Shut his mouth,” and he shoots Robespierre through the jaw, silencing him forever—making it impossible for a desperate D’Aubigny to learn where Madelon is. Robespierre is taken to meet Madame Guillotine.

D’Aubigny returns to Robespierre’s office and tears it apart. In despair, he tosses his torch to the floor in front of a bookcase, planning to burn everything. The torch reveals a stain on the floor that leads him to the secret room. He kills the Sergeant and rescues Madelon.

Outside the bakery, Fouché falls into conversation with an army officer as the crowd celebrates the death of Robespierre. Fouché, about to take leave of the officer, asks his name. The man replies, “Bonaparte. Napoleon Bonaparte.” Fouché, unimpressed, still promises to remember the name.

Cast
Robert Cummings as Charles D’Aubigny
Richard Basehart as Maximilien Robespierre
Richard Hart as François Barras
Arlene Dahl as Madelon
Arnold Moss as Fouché
Norman Lloyd as Tallien
Charles McGraw as Sergeant
Beulah Bondi as Grandma Blanchard
Jess Barker as Saint-Just
Wade Crosby as Danton