Dr. Edward Pretorius (Ted Sorel) is a scientist who has developed the Resonator, a machine which allows whoever is within range to see beyond normal perceptible reality. His assistant, Dr. Crawford Tillinghast (Jeffrey Combs), activates the machine and soon sees strange creatures in the air. When he is bitten by one of them, he urges Pretorius to turn the machine off. However, the crazed Pretorius refuses. Events transpire to the point where Crawford panics, fleeing outside. When the police arrive, they find Pretorius decapitated. Crawford is subsequently arrested and accused of murder.
Crawford is committed to a psychiatric ward, where he is treated by Dr. Katherine McMichaels (Barbara Crampton). After Crawford gives his account of Pretorius' death, Katherine orders that Crawford undergo a CAT scan, showing that Crawford's pineal gland is enlarged and growing. Convinced of Crawford's innocence, Katherine has him released to her custody, and plans on taking him back to Pretorius' house and the Resonator. They are accompanied by Detective Bubba Brownlee (Ken Foree), who investigated Pretorius' death.
Upon returning to the house, Katherine and Crawford rebuild the Resonator. Crawford reactivates the machine, which causes more creatures to appear. A severely deformed Pretorius, still alive, appears in the attic and tells the trio of a world beyond that is more pleasurable than normal reality. A panicking Crawford shuts off the Resonator, making Pretorius and the creatures vanish.
The next morning, Katherine insists that the Resonator could shed light on the victims of schizophrenia, as well as possible treatments and suggests that they turn the machine back on, but Bubba and Crawford disagree. While Bubba and Crawford are asleep, Katherine gets back up to feel the pleasure from the machine and turns it back on, bringing forth a worried Crawford and the now almost unrecognizable and mutated Pretorius. Bubba enters the scene as Pretorius grabs Katherine, preparing to eat her mind and take her to the world of beyond. Crawford and Bubba go down into the basement to shut off the power, but encounter a giant worm-monster. Bubba succeeds in shutting off the power, rescuing Crawford and Katherine and sending Pretorius away.
When Bubba decides that they should leave the house, all of a sudden, Pretorius somehow returns and the Resonator turns back on, as all three of them run up into the attic to deactivate it. Katherine and Crawford are attacked by little bee-like creatures, and as Bubba pushes them out of the way, he is devoured to the bone. Crawford fights off Pretorius and succeeds in freeing Katherine, but then his enlarged pineal gland pops out of his forehead. Katherine short circuits the machine by spraying it repeatedly with a fire extinguisher.
She then takes Crawford back to the hospital, where she is evaluated for insanity and schizophrenia, since her story was just like Crawford's. As Katherine is being prepared for shock treatment by a sadistic staff member, Crawford has developed an overwhelming hunger for human brains and kills Dr. Bloch (Carolyn Purdy-Gordon). Katherine escapes and drives back to the house with a bomb and a crazed Crawford following her.
Katherine puts the bomb on the Resonator and goes to leave when Crawford attacks her. As he is about to eat her brain, she bites off his pineal gland, reverting him to his senses. However, Crawford is pulled away and eaten by a completely deformed, mutated Pretorius. Katherine finally escapes, right as the whole attic explodes.
She lands on her legs, breaking one, and as the neighbors gather around her, she goes from sobbing to laughing hysterically as she tells them, "It ATE him!".Jeffrey Combs as Dr. Crawford Tillinghast
Barbara Crampton as Dr. Katherine McMichaels
Ted Sorel as Dr. Edward Pretorius
Ken Foree as Bubba Brownlee
Carolyn Purdy-Gordon as Dr. Bloch
Gordon had previously worked with both Combs and Crampton on Re-Animator, and he cast them in part because he had become used to working with a company of actors during his time in theater, and felt that doing the same thing with Lovecraft movies would allow the actors to know coming into the shoot that they would be asked to do "all sorts of odd things" and thus adapt more quickly to his direction. He was interested in the possibility of making a series of Lovecraft films with the same cast, like Roger Corman's Poe adaptations. Gordon, Combs, and Crampton would work together on a third Lovecraft adaptation in 1995, the direct-to-video Castle Freak, and Gordon would later direct versions of two more of Lovecraft's works: the film Dagon in 2001, and the second episode of the Masters of Horror television series, H. P. Lovecraft's Dreams in the Witch-House, in 2005. Many members of the production staff for Re-Animator also held similar roles in the production of From Beyond, including screenwriter Dennis Paoli, producer Brian Yuzna, executive producer Charles Band, director of photography Mac Ahlberg, and special effects artists John Carl Buechler and John Naulin.
Albert Band, who served as the production manager of From Beyond, also makes an uncredited cameo appearance as a wino.
From Beyond was shot in Italy with an Italian crew in order to save money. Gordon says that the film would have cost fifteen million dollars to make in the United States, whereas the foreign production enabled him to hold costs to approximately two and a half million dollars. It was shot on a soundstage called Dinocitta just outside Rome. Dinocitta was originally constructed by Dino DeLaurentiis, but was seized by the government for nonpayment of taxes, and then sold to Empire Studios. From Beyond was one of the first films shot at that venue during its period of ownership by Empire. Gordon shot his film Dolls at the same time, and it was released the following year.
As with his earlier film Re-Animator, Gordon made use of medical advisors to be sure that the actions taken by the doctors and nurses of the film followed proper medical procedures. Four separate special effects teams worked on the effects for From Beyond. According to Yuzna, the production ran out of money before the effects on the finale could be finished.
According to Gordon, securing an "R" rating from the MPAA was a challenging ordeal. He quotes them as initially saying his presented cut of the film had "ten times too much of everything". He was ultimately able to get away with making small trims, and without removing any entire sequences from the film. The Special effects was created by John Carl Buechler.
MGM has released a restored unrated cut of the film with extras. From Beyond has previously only been released in its edited R-rated form. The MPAA had required cuts to S&M footage and gore to allow it to be R-rated. This missing footage was reinserted into the film and the restored, longer version was aired on the Monsters HD Channel. This longer, "director's cut" version was also then subsequently released on DVD by MGM on September 11, 2007.
On March 26, 2013, Scream Factory released a Collector's Edition of From Beyond on Blu-ray Disc/DVD combo pack.
The film score by Richard Band won the award for Best Original Soundtrack at the Sitges - Catalan International Film Festival in Sitges, Spain.
The film received generally positive reviews from critics. On the review website Rotten Tomatoes, the film maintains a rating of 71% approval from critics, with an average rating of 6.7/10 based on 14 reviews.
Patrick Goldstein, film critic for the Los Angeles Times gave the film a positive review, writing, "From Beyond is a horror movie with some deliciously slimy tricks for the kids, but some shocking treats for grown-ups too".
Gene Siskel, film critic with the Chicago Tribune also enjoyed the movie, awarding it three stars out of four. Siskel wrote, "...From Beyond is a decent enough low-budget horror film that delivers what audiences have every reason to expect - a funny, horrific grossout".
William Wolf with the Gannett News Service rated the film half-a-star out of four. He criticized the movie for its strong gore content as well as the sado-masochistic treatment of women. In his review Wolf wrote, "The gore gets progressively more stomach-turning without much cleverness, and after a while From Beyond just becomes overkill, more revolting than scary or funny.
Allmovie's review of the film was favorable, writing "Gordon is that rare breed who truly finds inspiration in another creator and uses that inspiration to craft a film that captures the essence of that creator while still being totally and uniquely his own", calling it a "gory thrill ride of a movie."
In their book Lurker in the Lobby: A Guide to the Cinema of H. P. Lovecraft, Andrew Migliore and John Strysik write that "From Beyond is a visual treat," but add that the film's "gross sexual excess may displease hardcore Lovecraft fans."