Like many other European thrillers this early Italian giallo was obviously very influenced by the French film "Diabolique" with it's basic plot of a wealthy husband, wife, and mistress all scheming against each other. And like the later film "So Sweet, So Perverse" the movie throws another man (Jean Sorel)into the mix as a kind of a fourth side to the main triangle. This movie is no conventional thriller, however. For one thing it has kind of psychedelic, surrealist pop-art late 60's sensibility to it that always threatens to overwhelm (and occasionally does) the rational story-line. For another thing, it has a VERY bizarre setting, a fully-automated chicken plant. (There's a scene where the scientists at the plant create "monster" chickens without wings or beaks that really makes one want to swear off poultry for life). This unusual setting adds a whole industrial conspiracy angle and, moreover, a weird sort of social commentary to the proceedings.
The acting is all very good. Jean-Louis Tritigant plays a similar role to the one he'd later play in "So Sweet, So Perverse", but here he also might be a serial killer who is offing prostitutes in a roadside motel. Latin sex symbol Gina Lollabridga makes a rare appearance in this kind of film (which is actually much more entertaining than some of the bigger-budgeted movies she starred in)as the domineering wife. The young mistress is believably played by Ewa "Candy" Aulin, although she is not quite as enjoyable when she's not naked and not speaking in her natural (undubbed) heavy Swedish accent. (Aulin also appeared in another excellent, if even more obscure, giallo called "The Double"). The best thing about the movie though is the ending where EVERYBODY manages to get their just desserts--and then some. Definitely check this one out.