The Hulk was a hybrid of two popular comic book genres—monsters and superheroes. In The Incredible Hulk no. 1, Lee and Kirby introduced the emotionally repressed nuclear scientist Robert Bruce Banner, inventor of the gamma bomb. When teenager Rick Jones sneaks onto the bomb’s test site, Banner races into harm’s way to push him into a protective trench, only to absorb a vast quantity of gamma rays when the device detonates. The irradiated Banner consequently begins making nightly transformations into an enormous gray-skinned monster with virtually limitless strength and destructive capability; it embodies the darkest, angriest, and most antisocial aspects of Banner’s personality. Along with Jones, who was initially the only other person aware of Banner’s dual nature, the book featured a supporting cast that included U.S.