A speed-boat racer suffers amnesia after an (apparent) boating accident and goes to his isolated villa to recuperate. His relationship with his wife (Elga Andersen) is troubled, so he starts an affair (sort of) with the another woman (Roseanne Yanni), which results in one of the three of them being shot (in a catfight gone horribly wrong). But there are several more twists--and more murders--to come.
The Italian giallo is generally believed to have originated entirely with the work of Mario Bava and Dario Argento. But there was another parallel strain of the genre, which was a little more subtle and mannered (especially compared to the often bloody, over-the-top Argento films), that was clearly inspired by the seminal French thriller "Diabolique". These gialli, which include pre-Argento films like "Death Laid an Egg" and "The Sweet Body of Deborah" and director Umberto Lenzi's influential trilogy ("Orgasmo", "So Sweet, So Perverse", and "A Quiet Place to Kill"), all involve decadent members of the European "la dolce vita" jet-set crossing and double-crossing each other in ridiculously complicated sex and murder plots. This film is in that vein (even having a "Diabolique"-type twist where a character previously thought to be dead comes back to life).
The giallo genre of that time was blessed with many talented directors, including most notably Bava, Argento, Lenzi, Lucio Fulci, Sergio Martino, and Massimo Dallamano. The director of this is clearly not in that exalted company, but his work is certainly adequate. The ambiance of the isolated villa with one eerie, gnarled tree that seems to provoke hallucinations in the mind of the protagonist is very effective. And a scene at a modern disco where Rosanne Yanni shimmies to groovy music in a ridiculously short mini-skirt ensemble is definitely memorable. Some of your more horny and/or bloodthirsty giallo fans may be a little disappointed. The murders are not particularly effective and are hard to make out (at least in the dark, muddy print I saw). Andersen (or her body double) has nude scenes, but Yanni, while she nevers wears a lot of clothes, never takes them off either. Still, the plot is pretty entertaining, and the great Ivan Rassimov appears in an important supporting role. Not one of the best gialli, but still recommended.