Your Vice is a Locked Room and Only I Have the Key (1972)
When a film's title is that amazing it's a pretty safe bet that we're in giallo territory, and, sure enough, we are. But it's not fully in that camp. It's the story of a writer who abuses his wife and desires his niece, but by incorporating elements of Edgar Allan Poe's The Black Cat (1843) it attempts a more layered, sophisticated narrative. Unfortunately, with many subtexts fighting for attention it often feels like the component parts don’t merge together as well as they should've. It's a feeling that's somewhat overturned by the last third, although not completely. In spite of that, the performances from the principals are all great, which is something that gialli can't always claim to have.