Viva la vie! (1984)
Directed by Claude Lelouch

Film Synopsis

Michel Perrin, the head of the European division of a multinational company, and the young actress Sarah Gaucher would seem to have nothing in common.  Yet they go missing at precisely the same time, on the same day, and in the same manner, to reappear three days later as if nothing had happened.  Neither Michel nor Sarah can recall where they have been for these three days, but what is most bizarre is that they both have a large scar on the skull, in exactly the same place.  They also have the same uncontrollable urge to drink water.  Then, one day, the sun refuses to show itself.  On this day, Michel and Sarah suddenly recall what has happened to them.  At a press conference Michel reveals that he and Sarah were abducted by aliens to warn humanity that it must not go on squandering the world's energy supplies which they themselves are dependent upon...