In order to get to know his two French collaborators better, Henry Wydmark, director of a large American company, invites them to spend a weekend in the Alps. They consider this trip to be part of their job. But as the wife of one and the husband of the other are not free, they do not hesitate to leave their "heart under the mat" and hire one a husband of convenience and the other a wife fictitious. This misunderstanding will trigger a cascade of disasters.

An ambitious mobster plans an elaborate diamond heist while seducing the daughter-in-law of a ruthless mob patriarch as a determined police commissioner closes in on all of them.