FROM BEYOND

Dr. Edward Pretorius, a hedonistic and overly-ambitious scientist, has developed the Resonator, a machine that allows observers within its effective range to see beyond perceptible reality. His assistant, Dr. Crawford Tillinghast, activates the machine, sees strange creatures in the air and is bitten by one. Upon being notified by Crawford, Pretorius, driven by lust for power and knowledge, turns the machine on at full power and becomes mad with the feelings the Resonator causes. As the Resonator malfunctions, Crawford panics and flees. Police arrive to find Pretorius decapitated but bloodless. Crawford is arrested for murder.

In a psychiatric ward, Crawford is treated by Dr. Katherine McMichaels. After giving his account of Pretorius' death, Crawford undergoes a CT scan, which shows his pineal gland enlarged and growing. Convinced of his innocence, Katherine has Crawford released into her custody. The two, along with Detective Bubba Brownlee who investigates Pretorius' death, go to Pretorius' house.

After restoring the machine with Katherine's help, Crawford reactivates it. More creatures appear along with a naked Dr. Pretorius. His consciousness now altered and expanded, Pretorius tells of a world beyond that is more pleasurable than normal reality, and that his death was a means of ascending to this state of existence. Pretorius attacks Crawford, Bubba, and Katherine with slime-covered arms. Crawford shuts off the Resonator, making Pretorius and the creatures vanish.

Katherine thinks the Resonator could shed light on victims of schizophrenia and brain damage and suggests they turn it back on, but Bubba and Crawford disagree. While Bubba and Crawford are asleep Katherine turns it back on, bringing forth the now-mutated Pretorius. Pretorius grabs Katherine, preparing to absorb 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-like monster which attacks Crawford. Bubba succeessfully shuts off the power, rescuing Crawford and Katherine and sending Pretorius away.

Bubba decides they should leave the house. Pretorius returns, now able to manifest in our reality through his own willpower, and reactivates the Resonator, forcing his antagonists to run into the attic to deactivate it. Katherine and Crawford are attacked by bee-like creatures and as Bubba pushes them out of the way, he is devoured to the bone. Crawford fights off Pretorius and frees Katherine, but then his enlarged pineal gland forces its way out of his forehead. Katherine short-circuits the machine by spraying it repeatedly with a fire extinguisher.

She 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 develops an overwhelming hunger for human brains and kills Katherine's superior Dr. Bloch. Katherine escapes and drives back to the house with a bomb. A crazed Crawford follows her.

Katherine places the bomb on the Resonator but Crawford attacks her. As he is about to eat her brain, she bites off his pineal gland, causing him to come to his senses. Dr. Pretorius' will reconnects the severed wires of the Resonator and fixes the short-circuit damage. A mutated Pretorius returns and assimilates Crawford. Before Pretorius can do the same to Katherine, Crawford's consciousness fights for control within Pretorius; the opposing consciousnesses tearing their shared body apart. Katherine escapes through the attic window just as the bomb explodes, destroying the Resonator and killing both Pretorius and Crawford.

Katherine breaks her leg in the fall and the neighbors gather around her as she suffers a mental breakdown, saying "It ate him!" between mad laughter and crying.

Katherine short circuits the Resonator with a fire extinguisher, halting the monstrous events and escaping with Crawford, though both are left traumatized and institutionalized.

The ending underscores the catastrophic costs of unchecked curiosity and the pursuit of forbidden knowledge. Even as the immediate threat is stopped, the survivors are left fundamentally altered, highlighting Lovecraft’s theme that some doors, once opened, can never be fully closed.