Fourth (and final) giallo collaboration between director Umberto Lenzi and US star Carroll Baker. Martha (Baker), a young woman rendered mute as a child by the shock of seeing her parents killed in a train crash, lives with her Uncle Ralph (George Rigaud) in his villa in the Spanish mountains. One day her cousin Jenny (Ida Galli, here under the pseudonym 'Evelyn Stewart') - a successful singer - comes to stay. But that night Jenny is murdered by an unseen attacker, her body discovered the next morning by Martha. The police believe the killing is connected with the recent death of another young woman of similar type - blonde, slim, pretty. The police warn Martha to be careful as she also matches that description. A few days later a cat belonging to the daughter of a family friend is found dead with its throat cut, and soon after that Uncle Ralph's housekeeper Annie (Silvia Monelli) is found murdered in woodland, with a satanic goat symbol painted on a tree nearby; however, she's a different physical type (pretty, but slightly older, and darker haired and complexioned). As the killing continues Police now realise anybody could become a victim...
This differs from Lenzi's other work with Baker in that there's no sex/nudity, there's very little blood or gore, and the killings all occur offscreen (although we do see the aftermath). However, the film scores well on atmosphere (fog during the day, thunderstorms at night) and the locations are suitably gothic (sprawling villa, creepy cemetery). There's no shortage of suspects; Uncle Ralph (who spends all his spare time reading books on the occult); Ralph's creepy, looming chauffeur; the local doctor (whose movements couldn't be more suspicious if he tried); a devil-worshipping, drug-addicted, rough-sleeping, crazy-eyed hippy (based on Charles Manson - subtly named 'Mason')... and more. The problem is, once you discount all the way-too-obvious red herrings there's really only one person it can be. And sure enough... However, the performances (bar the wooden doctor) are good, with Baker definitely stealing the show. 6/10.