You won't be disappointed!

The film makes a home in your brain and the only cure is to see it again.

As somebody who had not heard any of this before, it became a curious phenomenon to sit and watch a film and slowly have the realities begin to click into place.

I think this is a new genre that they're all sort of working their way through it and haven't got all the kinks worked out yet but it's a genre that works for me.

Peter Weller makes enough money at his snooty office job to buy a brownstone in New York City, refurbish it, and then furbish it, all on his own. It's beautiful. It's exactly the way he wanted it, except for one thing -- a rat the size of a Scottish wildcat that drives him crazy with its catabolic antics. The reason for its existence, or even the existence itself, is a puzzle that may be called Schroedinger's rat.The beastly thing begins by chewing through the electrical cables and ends up by making a meal of some urgent work Weller has prepared for his job. The maintenance man gives Weller the lowdown on rats. They're cannibals, they bring plague and other diseases, they attack people's genitals, and can chew through a steel I beam. Weller uses mouse traps but the rat outwits him. This rat, by the way, has the IQ of a human being but a psychopathic one.The entire movie is a story of mano a mano combat between Weller and rat. The monster rat can drop or jump to the attack at any time, from any place. Weller is obsessed by his battle with the animal. Its noises keep him awake at night. He loses sleep and dozes off or daydreams at work, endangering his job. (His sympathetic but pragmatic boss is Lawrence Dane, who delivers a fine performance of which the film is unworthy.) The story becomes almost tragic as Weller isolates himself from friends and colleagues who would like to help him. They do what they can even though Weller has never told them that he's having a problem with a mutant rat. He becomes Howard Hughes. He refuses to answer the door or the phone and when an empathic woman from the office shouts to him from the sidewalk, we hear only hear his voice calling down distantly from an upper story, "Leave me alone." Weller's increasing estrangement is the best part of the film because the rest of the story is so ill handled, never missing a cliché. Thus, we hear scuttling noises in the ceiling and the camera takes the rat's point of view as it rushes through pipes and shafts. The musical score is pedestrian. Several shocking scenes presented as real are revealed as Weller's daydreams. The scenes of man/rat combat aren't convincing because there were no CGI's yet, so all we see is Weller screaming and demolishing his house with a weird studded weapon fashioned around a baseball bat. The happy ending comes out of nowhere and leaves all sorts of plot threads dangling. Weller's acting is up to par. His character is credible. We can easily identify with him, except for those moments when he's shrieking and being attacked by a damned rodent.

I saw this in the video store20+ yrs. ago. I like horror films overall. I liked the title, the blurb, and i like Peter Weller's acting. He is not over the top like Shatner or Walken. This movie has really good moments: the shadow on the wall, talking to the exterminator and trying to explain to his friends what is happening to him. I like it because it tries to use old school horror techniques: imply the horror instead of showing everything outright. I think if you allow your imagination to take over you will be really scared. To the point if you hear a sound you will do one of three things: hide under the covers, check the apt./house or call 911.

I gave this dandy nail-biter (no pun intended) nine stars as it is one of those movies that when found and decide to watch it I accepted the fact that it most likely is a low-budget waste of time. And most likely would bore me to sleep. I mean, really...What can anyone expect from a movie that only cost around 4 million to make. About ten or fifteen minutes into the flick it became obvious I would watch this one all the way to the ending roll of the credits.The acting is good, especially for this kind of movie. The camera shots and angles raise this movie up from the gutter and into the attic, a dark attic. Which this creepy old brown-stone building no doubt has.Never mind the nail clippers. The suspense in this thriller will keep your teeth gnawing on 'em just like a rat chewing on a lead pipe.If you are looking for an above average thriller I highly recommend, "Of Unknown Origin".Enjoy :0)

...and its still one of my favorites. The title doesn't really give an indication of what the movie is about. Tho the strangely preternatural rat co-star is indeed of 'UNKNOWN ORIGIN', it sounds more like a sci-fi title than a movie about Peter Weller being driven insane by an escalating rat problem in his house. Not just an ordinary rat problem, this rat is an advanced tactical model which manages to stay one step ahead of his human antagonist like some darkside Tom and Jerry cartoon.I even liked this better than the mother of all 'rat' movies, WILLARD. Weller can do no wrong in my book, hes consistently good and in fine 'Peter Weller' form here. Cant say I ever saw a theatrical release on this, possibly was direct to video. I have a copy somewhere that I recorded off HBO or something way back then. I didn't realize it was out on DVD, I'll have to track down a copy.