Das Paris der 20er Jahre: Ein Phantom spukt nachts durch die Göttersäle des Louvre. Neugierig geworden, beschließt der junge Journalist Jacques herauszufinden, wer - oder was - sich hinter der mysteriösen Erscheinung "Belphégor" verbirgt. An seiner Seite: Ein Meisterdetektiv, dessen clevere Tochter und eine undurchsichtige Femme fatale. Zwischen Jacques und dem Phantom beginnt ein wahnwitziges Katz-und-Maus-Spiel, in dessen Verlauf er selbst beschuldigt wird, Belphégor zu sein. Tatsächlich ahnt er nicht, wie gut dieser ihn kennt.
After the First World War, European powers decided that the small but affluent, and strategically important, Central European nation of Sokovia should become a monarchy. And so Boris, Count d'Esseck became Boris I of Sokovia. The dissolute philandering sovereign left a deputy to rule in his stead as Prime Minister, and now spends most of his time in Paris. But his debauchery grows ever more extreme and reckless, until in a fit of lecherous madness, he abducts the beautiful young artist Francine Gardannes!
The shadowy head of an underground army fighting to liberate India from British rule, Zapata has brought their ruthless campaign of terror to the streets of Paris. Having assassinated the young journalist and explorer Jacques de Villers at his own engagement party, Zapata's next target is the Paris head of the British Intelligence Service. When an elite secret agent is being stalked, taunted, and pursued by an unseen foe, who can they turn to for help?
Jacques Moret is the dashing man of the hour: a fearless flying ace, devoted to furthering aviation. But even as he enjoys the ball that aeroplane designer Florent Avrillé throws in his honor, dark forces are at work. Poison-pen letters accuse Moret of lusting after Avrillé's wife, the stunning but faithful Belle Antoinette, and of trifling with the affections of Avrillé's debutante daughter. Accusations and suspicions mount up, until only one man can uncover the truth behind this aviator's crime. Chantecoq. King of detectives, master of disguise.
Up and coming artist Jean Lachesnaye lives an idyllic life with his wife Yvette and infant son in Ker-Yvette, his villa on Brittany's Quiberon coast. But when a convivial dinner party gives way to a night of supernatural chaos, the dream begins to unravel. His servants abandon him, and during the course of a second nightmarish evening of ghostly incidents, his baby son vanishes, replaced by a sickly child at death's door.
When the Count de Roscanvel's body is found on the railway tracks, shot through the heart then hit by the Blue Train from Paris to Marseille, police accuse France's top young novelist and the count's beautiful wife is suspected of complicity. Harassed by the police and shunned by her family, there's only one place Countess de Roscanvel can turn to: a small house in Paris on Avenue de Verzy, home to Chantecoq, king of detectives, master of disguise.