Taking a page from the cursed Night of the Lepus (a film about giant killer bunnies, even if audiences had no idea beforehand), Warner Bros. did everything in its power to obscure the actual plot of this memorable, highly effective saga featuring one of the screen's most memorable rats. Promoted in the studio press materials as a "suspense thriller that charts the course of one man's victory over obsession" (technically true, but...), the Montreal-shot production from regular David Cronenberg producers Claude Héroux and Pierre David was a passion project for director George P. Cosmatos, a huge fan of the source novel, Chauncey G. Parker III's The Visitor. The film tones down some of the novel's more grotesque excesses but manages to make for an insanely entertaining 90-minute death match between Peter Weller, about to break through in RoboCop, and a persistent rat who's far more aggressive than the one seen in the same year's horror anthology, Nightmares.

Happy yuppie Bart Hughes (Weller) spends his days at a cutthroat Wall Street trust company with colleagues including Rituals' Lawrence Dane, so you know this can't end well. In his off time, Bart's happily living in a new brownstone apartment with his wife, Meg (Shannon Tweed!), and son Peter (Anderson). Bart's put a heap of time and money into converting the place into a sleek, modern luxury home, but when the rest of the family takes off for a vacation, things start to go awry. The first night the dishwasher floods the kitchen floor and something shatters a framed photo, so it's time to call in a plumber named Clete (Scanners' head buster, Del Grande) who says the culprit could be a rat. Bart's under the gun with two weeks to pull off a career-making project, but all that gets sabotaged by the crafty rodent who manages to outsmart rat traps, a strategically placed cat, poison, and other basic methods like threatening, "Just keep it up, I got friends in Jersey." When Bart accidentally drops the rat's babies down a grate, it's all-out war that will push him past the limits of sanity.

Thanks to a lackluster title, this film still hasn't gotten quite the following it deserves. There is a bit of a fan base from those who stumbled across it, obviously, but the insane escalation of the story is really a sight to behold with Weller pulling out all the stops as he descends into bat-swinging mania. The last 15 minutes is especially great, an impromptu home demolition that caps off the story on a wild note. There are some jump scares here and there, though anyone expecting a straight-up horror film may be a bit surprised as this is more of a mental breakdown film with some fun Willard-inspired rat mayhem thrown in every few minutes.

Long available on VHS (with again no mention of a rat anywhere on the packaging) and a cable TV staple, Of Unknown Origin first appeared on DVD from Warner Bros. in 2003 featuring a solid anamorphic transfer, the trailer, and a very welcome audio commentary splicing together separate recorded tracks with Weller and Cosmatos. The 2018 Blu-ray from Scream Factory is culled from a recent-ish HD transfer provided by Warner Bros. (and a big thank you for keeping the original '83 studio logo at the beginning), which initially premiered on some streaming platforms. It's about on par with other '80s catalog WB titles, preserving the intentionally gritty look of the film while bringing out more detail in the (many) dark scenes compared to the already good quality SD version. The DTS-HD MA English 2.0 audio sounds solid with most support given to the atmospheric Ken Wannberg score, and optional English SDH subtitles are provided. The commentary is ported over here and still makes for good listening, with tons of stories about how the film came about, the logistics of passing off Montreal as New York, Weller's admiration for Cosmatos' Massacre in Rome, and the movie magic involved in pulling off that climax. Screenwriter Brian Taggert appears for a new interview (17m57s) about how he got the gig after Visiting Hours and brought his own sense of humor to the project, including changes made to the main character along the way. Pierre David turns up next for a very funny interview (14m11s) about the glory days of the Canadian tax shelter film era, the quirks of working with the idea-spouting Cosmatos, and the process of shopping the script around other studios. The wildest of the three interviews is easily "Hey, Weren't You in Scanners?" (14m8s) with the very excitable Del Grande sharing the loopy story of how he ended up getting hired for his first significant acting role under false pretenses, became the promo face for Cronenberg's classic (and didn't make money off of it), and plenty more. The theatrical trailer (which tries to pass this off as a supernatural film) is also included, plus a gallery (2m54s) of stills and international poster art.

In 2026, Vinegar Syndrome upgraded the film with a two-disc UHD and Blu-ray edition featuring a new 4K scan from the original camera negative (with HDR-compatible Dolby Vision for the former option); as expected it improves significantly with a thicker film-like texture, warmer flesh tones, and finer detail, with the same framing and solid DTS-HD MA 2.0 English mono track (with English SDH subtitles). The Cosmatos/Weller track is carried over here along with the Pierre David, Brian Taggert, and Louis Del Grande interviews. A new commentary with Bill Bria and Ashley Coffin from Bill & Ashley’s Terror Theater podcast does a lively job of hitting all the major info points while going through possible interpretations of our protagonist's mental state, the handling of extras, the passing off of Montreal for New York City, and plenty more. In the amusing "Man vs. Rat" (21m52s), Weller opens up talking about his personal aversion to rodents and reptiles before launching into an account of his career at the time, his first meeting with Cosmatos (and their reunion on Leviathan), the supposed similarities of the source novel to Alien, and the lessons from Uta Hagen he used in his performance. Then actress Jennifer Dale appears for "Out of the Blue" (16m50s) covering her childhood acting days in Toronto, her move to Montreal just before doing this film, and her memories of working with Costmatos, and several of her other favorite roles. In "The Art of Rat" (7m34s), special effects artist Stephan Dupois looks back at doing this right after City on Fire, learning from Dick Smith alongside Carl Fullerton, getting recruited by the Heroux brothers, and having a free hand under Costmatos. The visual essay "Of Unknown Origin: From Animal Attack Movie to Urban Survival Thriller" (14m46s) by Samm Deighan surveys this film's place in the contemporary homicidal nature films (including other ferocious rodent epics like Deadly Eyes and Rats: Night of Terror) and appraises Weller's contribution as an unusual main character for this type of story. A thorough 8m35s locations featurette with Vincenzo Nappi walks through the small but memorable handful of exteriors sites, obviously focusing on the apartment building and the alleyway which pretty similar now. Two trailers and a 5m46s gallery of stills and promotional material are also included.

VINEGAR SYNDROME (UHD)

SCREAM FACTORY (Blu-ray)

Updated review on September 4, 2026