One of the films which helped make Charles Bronson a massive star in Europe (along with Farewell Friend and Once Upon a Time in the West) - although interestingly he's not the protagonist. That part is taken by Marlene Jolbert, the housewife who is stalked then raped by a mysterious bald man, who she then shoots dead and decides to bury without telling anyone, including her husband. Bronson pops up around 20 minutes or so in and seems to know a lot about what happened.
It's a funny sort of movie - I've heard it described as a little like Charade, which it kind of is because it's about a scared but beautiful and plucky woman meeting a mysterious man who knows more than he lets on, who treats her a bit roughly at first and seems to be a villain but actually is a goodie. Only Charade was better because Cary Grant changed identity several times, he and Audrey Hepburn fell in love and there were live stakes, i.e. the missing fortune.
Here Charles Bronson only changes identity once - he seems to be bad but is revealed to be good; also he and Jolbert don't fall in love - they develop an interesting rapport and grow to appreciate each other, but I feel it would have been better had the connection been stronger and they'd fallen in love. (They didn't have to get together at the end but there should have been love involved.) Also the stakes aren't as high - because the rapist has been shot dead, he's no longer a threat (maybe they should have employed an old Alec Coppel favourite... had her dispose of the body, thinking he's dead... but it turns out the person isn't dead after all), and the stakes then becomes about $60,000 in cash, which isn't that much... and there aren't really other people chasing after it.
This film has also been described as like an episode of Columbo which is perhaps a fairer comparison - because we see the crime committed and then the rest of the time we wait and see if the detective (Bronson) figures it out. Only that's not super satisfying because this is a movie and it felt as though it needed another twist or somethign.
I'd never seen Jolbert in anything before but thought she was great - a real cutie. She has some interesting character touches too, like an inability to swear, and throwing nuts against the window. Bronson impresses - he doesn't get that much of a chance to be a tough guy apart from one scene where he forces Jolbert to drink alcohol, and beats up some thugs in a bar, but he carries himself well, and he falls firmly into that French tradition of "weathered melancholic macho men" that includes Gabin and Belmondo. The two of them have a strong rapport.
The direction isn't bad though it never recaptures the spookiness of the opening sequence, with the stalker in the rain. Hitchcock very much an influence, as he was for so many French filmmakers. I'm still a little confused though exactly why this was such a hit in France.