First contact explores the initial meeting between humans and aliens, ranging from horrific tales of invasions to stories of benign visitors bearing the secrets of advanced technologies and world peace (or irony, as in The Twilight Zone episode "To Serve Man" -- the one that ended, "It's a cookbook!"). The meeting may occur on Earth, in space, or on another planet. H.G. Wells' War of the Worlds helped define the "alien invasion" variant of this subgenre.