With the help of his friend Nathalie, Arsène Lupin steals the “Queen's Necklace”, owned by the Dreux-Soubise family. The theft becomes an affair of state, a matter of concern for the Minister and the Prefect of Police. Herlock Sholmes, the English detective, provokes Arsène Lupin. They agree to give each other four days to find the necklace hidden by Lupin in his Normandy château.

In Cannes, Arsène Lupin, posing as a policeman, finds himself entrusted by Guerchard with overseeing an exhibition of solid gold statues. Kesselbach, one of the exhibitors, boasts of possessing an absolutely inviolable safe. But Lupin knows that the man murdered Professor Ramirez in order to retain sole possession of the Inca treasure. In his normal guise, Lupin pays Kesselbach a visit.

Avenging Joan of Arc and Trafalgar, Arsène Lupin robs the Tower of London. Fabulous booty: the Crown's treasure and, above all, a priceless parchment, a thousand-year-old relic shrouded in mystery, the secret of William the Conqueror. Herlock Sholmes is assisted in his investigation by the Intelligence Service, the French 2nd Bureau, Commissaire Guerchard and journalist Isidore Beautrellet. A scholar tells them that a copy of the famous parchment, of which he has transcribed indecipherable passages, was stolen from a monastery in Normandy five years ago...

After witnessing his fake death and funeral, Arsène Lupin prepares to go on vacation. A vacation they forgo to accompany a beautiful stranger, Catherine, to a Norman manor house where a mysterious “man in a black hat” is making menacing appearances.

The millionaire businessman Prévailles has just married the young dancer Jenny Saphir, whose career he has pushed. A few years earlier, Jenny had fallen madly in love with Lupin. Lupin, aware of Prévailles' activities, disguises himself to warn Jenny of the danger she's in, and to protect her. For she possesses the sapphire of Genghis Khan, a priceless jewel with a legendary curse, a gift from General Ignatieff, one of the dancer's previous admirers.

Arsène Lupin swaps his burglar's tools for those of a jeweler to steal ten million francs worth of diamonds. Dressed for the opera gala on behalf of diamond merchant Van Houven, model Régine, star of a major fashion house, is kidnapped.

Arsène Lupin assumes the identity of Prince Paul Sernine, invited to take part in Baron d'Aigleroche's hunts. Baron d'Aigleroche lives with his niece Hortense and cousin Gaëtan. Lupin covets a richly illuminated Book of Hours that the Baron keeps in a safe.

Following a car accident, Arsène Lupin finds himself in a Vienna hospital. Now completely amnesic, he is cared for by a beautiful nurse. And Inspector Pittora reveals that when he was found wandering alone in the countryside, he was carrying four passports, all valid, and a large sum of counterfeit money. Grognard, Lupin's loyal valet-driver, was found wounded near the car, taken to another hospital and unaware of his boss's whereabouts.

A timely shotgun blast from the Comte de Rougerac (alias Lupin) stops a train under which the beautiful Amélie is about to throw herself. Her only possession, a painting by Van Beuken, “La danseuse aux sabots”, has been stolen. The expert, Denger, having certified to the insurer, Blatt, that the painting was a copy, Amélie received only a ridiculous sum to compensate her for the theft. Lupin loves pretty women too much not to intervene in this dubious affair.

The famous American film writer Douglas Dutchman arrives in Germany aboard the Zeppelin. The press is there, as is the producer of his film, Siegfried Heidkamp, and the German star Brigitte Barett, who is to be his partner. After a triumphant welcome, Douglas Dutchman is invited to open an exhibition of jewelry belonging to Heidkamp's wife, Romy. During the rehearsal of the ceremony, Dutchman claims that the showpiece, the famous Ka-Hi-Dor diamond, is a fake. Everyone is stunned.

A beautiful woman at the wheel of a luxurious sports car... that's all it takes for Lupin to embark on a new adventure. Under the name Lutz Pindor, Count Pryberg-Artikoffen, of the Berlin Jockey Club, he travels to the splendid estate in the Bavarian Alps where Hélène (the pretty woman with the car) and her husband, Baron von Wiesenberg, have organized a horse-riding club. Lupin's arrival coincides with a macabre discovery: ride manager Hornung has just been murdered.

Irène Imbert's life in 1926 is no more edifying than her wartime escapades with American pilots showered in dollars. Her cynicism gives Arsène a brilliant idea. Posing as a notary, he comes to tell the young woman that one of his former “war godchildren”, Henry Bradford, has made her his universal legatee. As a result, Irène finds herself at the head of a considerable inheritance. In the meantime, crooks and shady financiers are jostling for position at her door.