Paul, is an ordinary man who divides his life between his shipbuilding company, his wife Elise and their daughter Mia. During a sea trip, Paul finds himself confronted with a strange, unexplained meteorological phenomenon. From then on, Paul shrinks inexorably, without science being able to explain why or be of any help to him. When, by accident, he finds himself a prisoner in his own cellar, and while he is only a few centimeters tall, he will have to fight to survive in this banal environment that has become perilous. During this experience, Paul will find himself confronted with himself, with his humanity, and will try to answer the great questions of existence.

Anna and Matheo's relationship is all but perfect when she meets Malik. Anna is confused about her sexuality and Malik's commitment issues are harboured by loyalty. La théorie du y is about how they find their way to live life through experiences, friendship and love.

Lucas has invented a new computer language but at the same time he has been informed about his strange terminal illness during which he has been gradually losing his memory. Shortly after that he meets Blanche who acts as a medium in a bizarre traveling show. Dying Lucas follows her to the sea resort where they spend together several days and nights.