All the world knows the exploits of Arsène Lupin, man of mystery, adventurer, and private detective—when it suits him! But of Lupin’s own personality not so much is known. He is obviously a man of infinite ingenuity; of iron will and determination; of irresponsible gaiety and imperturbable good-humour. He has a genuine fondness for poetic justice, as opposed to the brand represented by the Paris police force. He is whimsical, ironical, curiously detached—in fact, that’s half the secret of his success, that he never allows his life to be linked with the lives of other people. He is always the free-lance, playing a lone hand, trusting no one, relying solely on his own wits to extricate himself from the most perilous situation. For other people, including the public who delight to read of his escapades, he is always an urbane enigma, taking foul weather and fair with the same bland unconcern.

But now, a corner of the veil of mystery is lifted. For the first time, readers will find in this new adventure of the master-crook some indication of the Man behind the Mask. Arsène Lupin goes through life under a hundred aliases, a shadowy figure. But he is a human being like his fellows and can be moved by love and fear like other men.

As “Jean d’Enneris,” Lupin finds himself engaged in a curious duel with his old opponent, Chief Inspector Béchoux. The Mélamare Mystery finds Lupin working both for and against the police—rather in his “Barnett” manner. But whereas in previous cases of the kind he has had no personal interest in the protagonists, this time he finds himself losing his heart to the delightful little mannequin, Arlette Mazolle. At once, the case is much more than an affair of missing diamonds. Lupin must solve the mystery, but in doing so, he must protect Arlette. He is distraught to realize that she shares the dangers of the game. He is further harassed by the advent of a rival, almost as enigmatical as himself, on whom Arlette appears to bestow her affections!

So, though the beginning of the story finds “Jean d’Enneris” gaily flirting with Régine the actress in a box at the Opéra, the end finds him in a boat on the Seine with quite a different companion. But to arrive at this happy issue, he has had to wander in a maze of misunderstanding and dark intrigue; to solve a grim secret; and himself to face death with his beloved—to be rescued therefrom by his hated rival!

The Curse of a Century overshadowed the House of Mélamare, and struck chill on all who strove to thwart its purpose of evil—on “Jean d’Enneris” and Inspector Béchoux; on Van Houben, the diamond merchant, and Régine; on the Adrien and Gilberte de Mélamare; and—on Arlette.