A science-fiction film centered around planet Earth receiving a coded message from outer space and the subsequent disappearance of 12,000 inhabitants of Sepuvedra, a free-trade port. The government and the army are convinced that they have been kidnapped by aliens and Professor Larsen, an eminent astrophysicist and UFO expert, is assigned to lead an urgent investigative mission into the deserted town.

A dozen elegant people are gathered in a writer's desirable mansion. In the grand tradition of Agatha Christie, they all have something to hide.They begin a cruel game of truth, a game where you're not supposed to tell lies. As the questions become more and more intimate and precise, the tempers rise, while outside the storm is raging. Enter a hateful person (played by Paul Meurisse, the nasty headmaster in "Les Diaboliques") who seems to know a lot about them. Someone is murdered. Whodunit?

An American adventurer who has a gambling den in Istanbul, who is suspected to be involved in the kidnapping of a nuclear scientist, but ultimately becomes self on the search for the disappeared and gets a striving for world domination secret organization.