Ganja & Hess is a film about Dr. Hess Green (Duane Jones) and his struggle with addiction; in his instance, the substance he needs is blood because he is a vampire.
A successful and wealthy African-American anthropologist, the focus of his research is centered upon the Myrthians, a fictional ancient ethnic group of Africans. One of their cultural beliefs and practices are consumption of blood to gain immortality.
One evening at Green’s luxurious mansion, he and his new assistant, George Meda (Bill Gunn), are working on research. Soon after, George appears to be having a type of bizarre mental breakdown. Although it seems that the anthropologist allays his issues, soon after, George attacks Hess with a Myrthian ceremonial dagger and then commits suicide. Hess, surviving the wound, has an unusual urge and that is to drink the blood of George. This need is presumed to have been brought on by the weapon’s history and power and Hess quickly realizes that he is a vampire.