Crawford Tillinghast (Jeffrey Combs) is assisting Dr. Edward Pretorius on experiments in expanding the brain's power through frequencies. They open a portal to another dimension inhabited by unpleasant Cthulhu-esque creatures. The first things we see are these floating eel-like creatures and one of them bites Tillinghast. In the opening scene he's seen running away after someTHING emerged and the police arrest him. When they go up to the attic of the house they find Pretorius dead and missing his head. Soon after a psychiatrist, Dr. Katherine McMichaels (Barbara Crampton) visits Crawford in the mental institution and he insists a creature bit off his mentor's head. She interested in their unorthodox experiments.
I think this was Brian Yuzna trying to do his own REANIMATOR, by reuniting Jeffrey Combs and Barbara Crampton and loosely basing it on an H.P. Lovecraft idea. Nevertheless, it's a great "Mad Scientist" movie and a prime example of 80's horror.