“To love with your molecules is only possible at the beginning of a relationship,” theorizes Marguerite who has been married to Paul for five years; miraculously the molecules in their pairing are still at work. Except for one thing: they live in Montreal, and molecules do not like the cold! Paul, who works in a zoo, takes care of his sick son from another relationship and his father who is a clandestine immigrant. Marguerite is terribly bored then one day her molecules explode and she runs away with the brother of the parish priest…