Nora(Letícia Román)comes to Rome to visit her sickly aunt and finds herself embroiled in a murder mystery. After her aunt dies, Nora walks out into the dark, quiet Rome streets in shock, sees a female victim with a knife plunged into her back, and a brief glimpse of a man before fainting. Awakening in a hospital(great point-of-view shot of nuns standing over her),she tries to convince her attending physician, Dr. Marcello Bassi(a young, dashing & charming John Saxon)that she witnessed a murder. When no body is found, Nora still persists the fact that she saw this woman with a knife in her back and a killer drawing near. Shortly after attending her aunt's burial, a wealthy citizen nearby named Laura Craven-Torrani(Valentina Cortese)out-of-the-blue offers Nora a place to stay claiming she knew her aunt. Claiming that she was on her way to Switzerland, Laura allows Nora to remain in the house alone..the question is, why is Laura so generous? Nora, undaunted despite the idea of danger(..and the fact she often reads murder mysteries with the thrilling idea of partaking in one obviously motivating her participation in finding the murderer),will pursue the identity of the killer of that missing woman. Marcello, at first reluctant, decides to assist Nora in her sleuthing, falling for her in the process. Marcello even serves as host to Nora showing her Rome and it's many sights(..I felt this was Bava disguised as Marcello bestowing foreign audiences with the place he adores). While staying in Laura's home, she encounters a metal box with newspaper clippings of the notorious, supposedly solved, Alphabet Murders, detailing the serial killings of various women following a distinct pattern, a knife in the back with each female victim's last name starting in alphabetical order. Could Nora be the next victim? During their search, Nora and Marcello encounter a broken, pitiful former newspaper reporter, Andrea Landini(Dante DiPaolo)who followed the Alphabet Murders case and felt responsible for putting the wrong man behind bars for the crimes.

Bava's visual eye shows wonderful things as he shoots this film in B&W displaying a type of Rome both beautiful and, at the same time spooky, equipping the surroundings with the right pinch of dread and danger. The night time scenes are especially atmospheric as any body could be hiding in the dark, with a chance to murder without being caught. I also loved how Bava shoots Laura's house at night with a frightened, cautious Nora often looking over her shoulder as wayward shadows loom thereabouts. You never feel Nora is completely safe, even with Marcello often by her side. If you read the signs, you might figure out who the killer is..I think that mystery can be easily solved by those who have seen their share of gialli and murder mysteries. It's Bava's fantastic presentation that provides the thrills. It doesn't matter whether Bava shoots in B&W or color, he knows how to frame a stunning shot and add just the right amount of ambiance to it.

A first-time watch for me of Mario Bava's THE GIRL WHO KNEW TOO MUCH (1963, original title La ragazza che sapeva troppo),widely regarded as the first giallo film. I'd say that this is more of a proto-giallo as it has some elements and ideas that would become prominent in the genre while at the same time part of it feels very much like a romantic comedy instead - almost like a local version of ROMAN HOLIDAY complete with a flirtatious John Saxon and Leticia Roman as the put-upon protagonist at the mercy of an inexorable fate.

The opening scenes are nicely handled, keeping you guessing and introducing one of those witness-to-a-murder sequences that Argento would go on to popularise when he came to the genre the following decade. Bava's cinematography is quite excellent throughout; this was his last black and white movie and he makes the very best of that format, particularly in regard to shadow and lighting. I've got the Arrow blu-ray and of course it looks fantastic in high definition. Don't go in expecting gore murders or bags of creepy atmosphere, as this is tonally much more a light comedy while paying tribute to the murder mysteries of Agatha Christie and the like. Some of it gets a bit absurd, like when Roman sets up the string trap in her apartment, but a lot of it is likeable, particularly Saxon as the accident-prone love interest. Bava would go on to fully immerse himself in the genre with his next giallo, the all-time classic BLOOD & BLACK LACE.

A young tourist arrives in Rome and witnesses a brutal knifing. The assailant then attacks her and she awakens in the hospital. She apparently had been talking about the murder in her delirium and a police investigator is nearby. He dismisses her story as just a dream and no one will believe her that it occurred. In fact, doctors then arrive and talk about how she is a neurotic and probably imagined the incident due to alcoholism or a bump on the head! The woman just catch a break from these jerks! The only one who will even listen to her is a young doctor (played by American actor, John Saxon)--though he's also convinced the incident never occurred.

A bit later, the young lady meets a woman about her age that takes her under her wing. This new friend comes on a bit strong and even invites the lady to stay in her home while she's away in Switzerland. This and the fact that the house is on the same square where the murder apparently took place would certainly seem to be good reasons to decline the offer--but she does not! There, alone in the house, you know something bad will happen! Leave, lady...leave!!! But, she doesn't and again and again, it looks like she's just imagining all of this.

This is a very creepy and atmospheric thriller from famed horror director Mario Bava--who made a lot of other cool films in his career, such as "Danger: Diabolik". His films are seldom dull--and this one is no exception. Exciting and with lots of nice twists.

By the way, in an odd casting decision, the Italian actress Letícia Román was cast in the lead as an American. And, American John Saxon was cast as an Italian! Talk about weird...but it somehow worked!