In the second episode of the trilogy Fantômas kidnaps distinguished scientist professor Marchand with the aim to develop a super weapon that will enable him to menace the world. Fantômas is also planning to abduct a second scientist, professor Lefebvre.

Fantômas is a man of many disguises. He uses maquillage as a weapon. He can impersonate anyone using an array of masks and can create endless confusion by constantly changing his appearance.

A few stories about marriage and its problems. Antoine is about to marry Gisèle. His friend Julien, an established bachelor, desperately tries to convince him not to do it, recounting his own painful experiences.

A chaotic family go on holiday to Spain and get mixed up with a gang of diamond thieves.

JAM (Christian Clavier), a French "master of the universe" is on the brink of a major takeover when he starts suffering from anxiety attacks. His doctor (Lhermite) thinks it is to do with childhood experiences and suggests he searches back in his mind to something that could be the trigger and will prove to be the antidote.

Paul Martin is the subservient brown-nosing youngster who needs quick advancement up the hierarchy to pay for the modern lifestyle he is buying on credit. Seeing that marrying his immediate superior's daughter will not get him the results he wants, he begins plotting the demise of the head of the company. The company itself specializes in holiday travel and unscrupulously brutalizes its customers for maximum profit, spending more thought on publicity gimmicks than customer service...

The evil knight Torchesac, who is at the service of the sinister lord of La Mortaille, gets a very powerful magic flute and uses it for evil purposes. Johan and Pirlouit, assisted by the magician Homnibus, travel to the land of the Smurfs, the only manufacturers of this sort of instrument, to get a new one and battle the usurpers.

The film is biographical, telling the story of the life and artistic struggles of the French composer Hector Berlioz. Berlioz is shown as a recalcitrant medical student in an anatomy class dreaming of becoming a composer; at a demonstration during a performance at the Paris Opéra conducted by Habeneck; at supper with other young artists (Hugo, Janin, Dumas, Mérimée, Delacroix); and chasing after his future wife Harriet Smithson, after a performance of Hamlet. Also depicted are his life in a garret, while suffering from an illness due to an abscess in the throat; a visit from his mother who curses him; and the composition of the Symphonie fantastique. The film then shows his marital breakdown, the premiere of his opera Benvenuto Cellini, his travels throughout Europe, his second marriage to Marie Recio (called "Marie Martin" in the film), public acceptance in old age and reconciliation with his son.

JAM (Christian Clavier), a French "master of the universe" is on the brink of a major takeover when he starts suffering from anxiety attacks. His doctor (Lhermite) thinks it is to do with childhood experiences and suggests he searches back in his mind to something that could be the trigger and will prove to be the antidote.

Arsène Baudu and Hyacinthe, a pair of small-time crooks, fall prey to Alexandre Larsan-Bellac, who involves them (against their will) in high-profile swindling, but their success is quite limited. For starters they are deceived by Mrs. Paterson, a charming widow. Later on, Ribeiro, a Portuguese contractor and former victim of the two crooks, traces them and forces them to work on one of his building sites for damages. Just then, Larsan-Bellac resurfaces with plans to lure Ribeiro once again. —Guy Bellinger