Professor Marcilly is a famed brain specialist who, following in-depth and extended research work, is now able to perform brain transplant surgery. One day, he finds himself in the presence of a young car accident victim for whom the only hope of survival would be a brain transplant. Marcilly, who has a heart condition and is terminally ill, decides to become the "donor". The operation is a success. But who is actually the patient discharged from the hospital: a young fellow with the brain of a young man or an old man in the body of a young one?
Saleswoman Jenny is crazy about the painter Jack. But Jack does not want to marry, even though he loves Jenny passionately. So Jenny looks elsewhere to find the right man. She marries twice, but always ends up back with Jack and gives herself to him with no attachments. Will Jack and Jenny find true love? Of course!
A professor experimenting in suspended animation accidentally shrinks his dog and later, his female lab assistant, when she drinks the liquid by accident and shrinks to 3 inches tall. The professor keeps her in his pocket until he can find an antidote. Sometimes she's naked, too.
A strike has broken out in a big factory in the North of France. Two workers, Robert and Etienne, go through the experience in a different way. Etienne, who has worked there since the start, is still influenced by the time when workmen and their bosses found an agreement directly. Unlike him, his young friend believes in the power of labor unions. He even goes to Paris to attend special classes in trade unionism.