Edward Jessup, a young psycho-physiologist, experiments with different states of consciousness, obsessed with an addiction to truth and knowledge. He injects himself with psychedelic drugs, lies locked in an isolation tank and experiences all the stages of pre-human consciousness until finally terrible changes take place with him: Jessup also physically transforms into a pre-human being. His thirst for knowledge drives him into ever new, increasingly irreversible transformations. Only the horror when his body begins to dissolve into pure energy brings him back to human bonds...

Paddy Chayefsky (January 29, 1923 – August 1, 1981), one of the most important US dramatists, wrote a breath-taking, equally philosophical shocker with his debut novel.

In 1980, British director Ken Russell adapted the novel based on Paddy Chayefsky's screenplay - starring: William Hurt, Blair Brown and Drew Barrymore.