Sssssss

Doctor Carl Stoner is an eminent herpetologist. For 30 years he has devoted his life to the research of snakes and the venom that he extracts. Requiring the aid of an assistant, Dr. Stoner hires the young research aide, David Blake.

David meets Kristina, Stoner's daughter, who also works on the research with her father. To immunize him against possible bite of snake, Stoner submits David to series of injections of a product based on cobra venom, the king of snakes whose injection is instantaneously fatal. That evening, David falls to sleep and discovers the hallucinatory effects of the cobra's venom. Thus, Stoner does one injection a day to David for a month. David does not put doubts on this practice, nevertheless he notices strange things...