MAP21: One Flew Over The Caco's Nest (called One Flew Over the Cacos Nest [sic] on the intermission screen) is the twenty-first map of Alien Vendetta. It was designed by Pablo Dictter and uses the music track "Grove" from Hexen. It was one of the few maps to remain unchanged from the first release to the second. The title of this level is a pun on the title of the novel One Flew Over the Cuckoo's Nest by Ken Kesey (made into a Broadway play in 1963 and a film in 1975), and the name of the Cacodemon.