many of the persons, places and events described in the Discworld books and their counterparts in myths, legends, fairy tales and folk customs on Earth. Other writing Pratchett's first two adult novels, The Dark Side of the Sun (1976) and Strata (1981), were both science fiction, the latter taking place partly on a disc-shaped world. Subsequent to these, Pratchett mostly concentrated on his Discworld series and novels for children, with two exceptions: Good Omens (1990), a collaboration with Neil Gaiman (which was nominated for both Locus and World Fantasy Awards in 1991), a humorous story about the Apocalypse set on Earth, and Nation (2008), a book for young adults. After writing Good Omens, Pratchett brainstormed with Larry Niven on a story that would become the short novel "Rainbow Mars". Niven eventually completed the story on his own, but states in the afterword that a number of Pratchett's ideas remained in the finished version. Pratchett also collaborated with British science fiction author Stephen Baxter on a parallel earth series. The first novel, entitled The Long Earth was released on 21 June 2012. A second novel, The Long War, was released on 18 June 2013. The Long Mars was published in 2014. The fourth book in the series, The Long Utopia, was published in June 2015, and the fifth, The Long Cosmos, in June 2016. In 2012, the first volume of Pratchett's collected short fiction was published under the title A Blink of the Screen. In 2014, a similar collection was published of Pratchett's non-fiction, entitled A Slip of the Keyboard. Pratchett wrote dialogue for a mod for the game The Elder Scrolls IV: Oblivion (2006), which added a Nord companion named Vilja. He also worked on a similar mod for The Elder Scrolls V: Skyrim (2011), which featured Vilja's great-great-granddaughter. Children's literature Pratchett's first children's novel was also his first published novel: The Carpet People in 1971, which Pratchett substantially rewrote and re-released in 1992. The next, Truckers (1988), was the first in The Nome Trilogy of novels for young readers (also known as The Bromeliad Trilogy), about small gnome-like creatures called "Nomes", and the trilogy continued in Diggers (1990) and Wings (1990). Subsequently, Pratchett wrote the Johnny Maxwell trilogy, about the adventures of a boy called Johnny Maxwell and his friends, comprising Only You Can Save Mankind (1992), Johnny and the Dead (1993) and Johnny and the Bomb (1996). Nation