A Blade in the Dark (1983)
Director: Lamberto Bava, Andrea Occhipinti, Anny Papa, Fabiola Toledo
Ah, the first giallo of my marathon. For those unfamilar with giallo, they're a genre of Italian horror movie popular in the 70s and 80s. They're a kind of gory crime thriller, always with a mystery killer who's revealed at the end, and are famous for stylish camera work. The most famous giallo directors were Dario Argento, Mario Bava and Lucio Fulci.
A Blade in the Dark (that's the US title, the Italian one was Casa con la scala nel buio, which translates as "House of Dark Stairs") is directed by Mario Bava's son Lamberto, probably best known for his series of Demon movies.
Sadly, Lamberto's effort here doesn't measure up to that of his father or Argento. It's stylish enough, with some good suspense moments and an intriguing "whodunnit" aspect, but there's just something missing. I can't quite put my finger on what it is, but A Blade in the Dark falls short of what I expect from a giallo.
This is worth watching for the giallo completist, but if you are new to the genre, look elsewhere first. Start with a classic like Profondo Rosso (Deep Red) or Twitch of the Death Nerve.