First of all, it stars Jeffrey Combs, or as you may be more familiar with, Dr. Herbert West. It is also directed by Stuart Gordon, director of Re-Animator.
Here's what it's about: Combs plays Edgar Allan Poe near the middle to end of his life. He's a drunk, he's low on cash and his wife (his cousin, of course) has TB. He's also hit a rut creative-wise. While he's trying to come up with a new story, their black cat seems to torment him and distract him at every turn. It gets to bad that Poe attempts to kill the cat, while he inadvertently burns down his house. Forced to move elsewhere, he is driven crazier still by the fact that the cat still seems to be alive, haunting him.
You can usually tell a stage actor when you see one on screen - Jeffrey Combs is a great performer and you can see his transformation from crazy to crazier and drunker. I really think we should see him in more features.
One of the great benefits of this series is that the directors are allowed almost total creative freedom, which they never seem to enjoy while making feature films. They also assured a certain budget that the feature benefits from. In this instance, there are two things to point out: first, you can tell Stuart Gordon is a low-budget director with low-budget sensibilities. A lot of times, characterization and story are emphasized. Secondly, those of you who remember Re-Animator remember that there's a certain amount of camp value because the gore is so ridiculous-looking, albeit well planned. From the almost sickening gore of Black Cat, you can imagine what he would've been capable of had Re-Animator would have looked like had he more money.
Good story (especially for Poe fans, like myself), great performances, great gore.
EDIT: After spinning this again and paying close attention to the opening credits of this feature, I found a really good explanation for the level of gore. In addition to Stuart Gordon really liking gore, the opening credits revealed that a certain Gregory Nicotero put some work into this feature. Can't believe I missed that one.
