We all know it - you must not step on the lines of the flagstones. It brings you bad luck. And isn't there something with figures? To some people it develops into true obsession, and it becomes a strain. Søren is one of them. The day consists of a number of more or less mad rituals, which a psychologist, Søren's parents and ex- girl friend try to explain. Is it possible to explain Søren's case?