The tackiness of the mise-en-scene, intentionally or not, made me queasy! Or perhaps it was just cheaper than most 1960s films I've seen and so felt like a weird cardboard facsimile of the much more colourful "real" 1960s (even though the latter image is just as constructed and clearly further from day-to-day reality!) Reminded me of watching one of Roald Dahl's 'Tales of the Unexpected'. Ace cinematography though.
Somewhat predictable thriller with a couple of shocking, suspenseful moments and good performances from Signoret, Caan, and Ross. The movie really begins to drag after the first half hour and doesn't recover until near the end. The best thing about it is the cinematography by William A. Fraker, who would later be nominated for six Oscars.