Harvard research scientist Professor Eddie Jessup (Hurt) is experimenting with a water isolation tank, floating nude in complete deprivation of sight, sound, touch, or smell. Using the water tank and psychedelic drugs seems to turn his molecular structure backward in evolutionary time. He is hooked up to monitors to record the vital life signs he experiences while in the tank. Strangely aberrant readings emit from the tank; heightened breathing, pulse, brain activity, etc.
His wife Emily (Brown) and colleague Mason Parrish (Haig) are concerned about the research and where it is leading Jessup. He travels to the American Southwest as part of his research and he ingests a hallucinogenic mixture supplied by the local Indian medicine man. He travels outside his own consciousness. He finds when he returns back to the university and uses the isolation tank again he devolves into a primitive state of being where he is now a small ape-man. Brandishing a club, he attacks a guard and runs amok. He wakes up in the ape house at a local zoo with blood around his mouth. Hurt finally devolves into glowing fundamental molecular matter and is only brought back by the tactile embrace of his wife.
The review of this Movie prepared by David Fletcher