In The Amazing Spider-Man #122 (July 1973), Harry's father, Norman, is killed off, and a subplot leading to Harry Osborn inheriting his father's identity as the Green Goblin is introduced. This subplot culminates in The Amazing Spider-Man #136 (September 1974). Writer Gerry Conway said that the idea of Harry Osborn becoming the Green Goblin stemmed in part from a desire to deal with the consequences of the psychedelic drugs Harry began using in The Amazing Spider-Man #96 (May 1971). Conway said that he had had experience with such drugs himself, and that "with psychedelic drugs, hallucinogens, if they've been misused, there's a potential for additional hallucinogenic experiences that are completely beyond your control or volition. I could imagine Harry getting hit by something like that, in the fragile emotional state following the death of his father, and losing touch with reality, as a result. Besides, I never had any intention of getting rid of the Green Goblin as a concept forever, so it all came together. "