Threshold may refer to: In fiction: Threshold (Doctor Who), organization of Gallifreyan/Human origin in Doctor Who comic strips Threshold (fictional planet), the planet around which the ringworld Halo orbits in the video game Halo Threshold (comics), comic book character from Wildstorm Threshold (novel), a 1985 science fiction novel by David R. Palmer Threshold, a 2001 science fiction novel by Caitlín R. Kiernan The Threshold Project, a plot element from Sierra's PC game "Threshol… (More on Threshold)