In the early 1960s, when Neil Gaiman was eight years old, he read a story called "The City on the Edge of Forever" in the collection Star Trek 2. The piece was an adaptation of a Star Trek teleplay that had been written by one Harlan Ellison. Two years later, Gaiman read a story called "I Have No Mouth, and I Must Scream" in the anthology World's Best SF Third Series. This hallucinatory, post-apocalyptic tale of four humans trapped inside a sentient and psychotic computer had such a terrifying effect on Gaiman that he looked up its author. Ellison had written it too.
Source: Washington Free Beacon