This is the best interpretation of this play by D. B. Priestley that I have seen so far! Compared to it, both the 1979 Soviet adaptation with Y. Budraitis and the quite worthy 1973 TV play with V. Etush are not exactly 'resting', but certainly recede into the background.
Typical of Priestley's technique: a seemingly insignificant incident sets the hidden springs in motion, and now the winding mechanism is unstoppable, and the unsightly secrets of outwardly decent people one after another come out into the light. By the way, Soviet productions in one way or another led the viewer to the idea that the root of evil - in social inequality. Maybe Priestley could have had that in mind, too. But I think he was much more concerned with what was going on in the soul. For example, the phenomenon of human conscience.
The movie is shot without any special frills and, except for a few flashbacks, in the interiors of one room. Naturally, all the attention here is focused on the acting ensemble. He does his job brilliantly, but Alastair Sim is something special.
The image of Inspector Gull, created by Sim, is a mastery bordering on magic.
As the screen fades out, you can't get out of your head that serene figure rocking serenely in his chair with an inscrutable smile on his face and all-knowing eyes. As an embodied allegory of the coming retribution for all the evil we do to our neighbor, even if unknowingly.