Achillis Saturnin, making a meagre living as one half of the "Siamese twins", a ridiculous circus act, inherits a dazzling sum of 159 million francs, only to have his double steal it behind his back. The impostor installs himself in the mansion of the deceased, adjusting smoothly to an overdone servant-keeping-class kind of lifestyle.
But more rivals lie in wait; a spooky sect under the name of Ku-Klux-Eiffel, known for jamming French broadcasts with coded messages transmitted from the Eiffel tower, comically terrorize the impostor down to his nightmares. Driven to panic, the man goes into hiding in Paris, where he discovers that Achillis, Silvanie and her younger brother, have lost their job at the circus and are dependent on alms.
Afraid to return to the mansion himself, he sends Achillis to fill in his place in promise of 500.000 francs. Achillis agrees. While living it up, throwing parties and such, he is kidnapped by the Knights of Ku-Klux-Eiffel who take him to their castle high up the mountains. Taking it for a prank at first, Achillis only manages to escape at the very last moment. Along the way he gets hold of the key to the Ku-Klux-Eiffel code and one of their receiving devices. Able, thus, to intercept their messages he gains in to exposing the entire sect.
It takes another kidnap and escape through a labyrinth, the unmasking of a human chameleon, getting passed the mysterious Li-Ho-Ha (a creepy, apparently Chinese-or so adviser of the sect's leader), and the notorious Eiffel-tower-climb to bring this marvelous film to a happy end.
Source : IMDb