"The Incredible Hulk" is based on the popular comic book tale of the metamorphosis of a scientist who achieves mysterious superhuman strength when he is angered. Bill Bixby portrays scientist David Banner, who, while doing research on the incredible feats of strength accomplished by some individuals during moments of stress, is exposed to a massive dose of gamma rays. He feels no ill effects, but the first time he loses his temper afterwards, he is transformed into a bizarre man-beast nearly seven-feet tall with enormous strength. When his anger subsides, he returns to his original appearance. With the aid of a fellow researcher, Banner tries to reverse the process which has upset his chemical makeup. Their efforts are thwarted by a nosy reporter specializing in sensationalism, with tragic results.