Crawford Tillinghast (Jeffrey Combs) has been developing a machine called "the resonator", which will allow humans to experience an extra dimension. However, there are creatures inhabiting the extra dimension, creatures from beyond our dimension. Crawford's supervisor, Dr. Pretorius (Ted Sorel), has an early encounter with the creatures, and the event leads to a murder scene with a decapitated body whose head cannot be found, the resonator destroyed, and poor Crawford locked up in a mental institution with an unbelievable story.
After a visit from Dr. Katherine McMichaels (Barbara Crampton), Crawford is released into her care under the supervision of officer Buford "Bubba" Brownlee (Ken Foree). The three return to the house where the first incident took place in an effort to help Crawford explain what happened to Dr. Pretorius. However, once Crawford repairs the resonator, the creatures begin to appear again...along with a changing Dr. Pretorius.
Stuart Gordon & Brian Yuzna created this adaptation of H.P. Lovecraft's short story by the same title. This is also the second film that Jeffrey Combs and Barbara Crampton starred together in since Re-Animator. Ken Foree, who is better known for his role in Dawn of the Dead, once again portrays the tough guy that the audience can easily side with. Ted Sorel's performance encompasses everything that one could hope for in a mad scientist.
While the movie itself is filled with special effects that can equal those of today's movies, and a story that is truly original, it was relatively unknown or unseen by many moviegoers because of its limited availability in VHS format. However, a little more than 20 years after its initial debut, the movie was finally released on DVD, along with commentary by cast and crew, deleted scene, and storyboard.