One of the best-known episodes was the 1963 installment "Nightmare at 20,000 Feet," which starred a young William Shatner (later cast as Star Trek's Captain Kirk) as a man convinced that a hideous monster is lurking on the wing of the airplane in which he is traveling, even though nobody else can see it. That episode helped launch the career of Shatner, as well as a film version and a revival series during the 1980s. ABC twice attempted their own science fiction anthologies, first with 1959's One Step Beyond, then with 1963's The Outer Limits. (ABC briefly tried to hire Serling after The Twilight Zone ended, but Serling noted that ABC's proposal was more horror-oriented in that it "booked (him) into a graveyard every week" and turned the network down.) Although The Outer Limits had a much shorter run, finishing in 1965, it proved to be famous and influential as well. Like its CBS contemporary, it spawned an only moderately successful revival decades later. One Step Beyond survived in frequent reruns because its owner, Alcoa, abandoned the copyright. Return of the adventures series Irwin Allen, who later went on to produce famous 1970s disaster movies like The Poseidon Adventure and The Towering Inferno, produced a whole range of popular science fiction series shows on American television during the 1960s. These included Voyage to the Bottom of the Sea (1964-1968), The Time Tunnel (1966-1967), and Land of the Giants (1968-1970). All involved futuristic, scientific concepts played out as the background to glossily produced action/adventure shows. Critics of Allen’s output often argue that it is all rather soulless and shallow, but as mass-produced entertainment it proved popular with American and international audiences. A popular non-Allen production was The Wild Wild West (1965 to 1969) which incorporated classic Western elements, espionage thriller and science fiction/alternate history concepts (in a similar vein to what would later be called steampunk). The mid 1960s would prove to be an important period in the history of US television science fiction. It saw the creation of two brand new "space opera"-based science fiction shows, both featuring broad galactic exploration themes, with each show dealing with them in very different manners. The first of these was Irwin Allen's CBS show Lost in Space, which ran for three seasons from 1965 to 1968, and the other series, which premiered on NBC in 1966, was Star Trek. Star Trek and its