Edward Jessup (
William Hurt) is a university professor of
abnormal psychology who, while studying
schizophrenia, begins to think that "our
other states of consciousness are as real as our waking states."
[2] Jessup begins experimenting with
sensory-deprivation using a
flotation tank, and he travels to Mexico to participate in what is apparently an
Ayahuasca Ceremony, although his guide states that the Indigenous tribe they are meeting works with
Amanita muscaria which they are collecting for next year's ceremonies
