The congenial duo of Komorowska and Zapasiewicz in a small flat brought tension which sparkles even now, after so many years. Jan - self-confident, exaggeratingly polite associate professor, cool, orderly, organised, absolutely devoted to his work in a laboratory and successful in his work. Marta - a chemist, like him, but an unsuccessful one, oversensitive, she paints mediocre copies of famous pictures in her spare time. They are both lonely, but they cope differently with the loneliness. They live in the same block of flats, almost behind the wall. For Jan their encounter is a forced politeness and for Marta - a desperate search for closeness.
The irony of Behind the Wall lies in the fact that at the beginning the viewer sides rather with the scientist and not his neurotic neighbour and the roles turn in the final scenes. This low-key TV film is an artistic masterpiece. It was enthusiastically received by a wide audience. After it was screened, industry magazines and television headquarters were flooded with letters from disturbed viewers. At the viewers' request there was even a TV debate of scientists based on Zanussi's film.