Written by Terry Nation, "Mission to the Unknown" (aka "Dalek Cutaway") was one of the few single-episode Doctor Who adventures. None of the series' regulars appear in this story; instead, the action is dominated by Space Agent Marc Cory (Edward de Souza). While investigating the activities of the Doctor's perennial enemies, the Daleks, Cory is put in the unenviable position of saving the universe from the villainous mutants. Originally telecast on October 9, 1965, "Mission to the Unknown" was intended as a preview for the upcoming Doctor Who story arc "The Dalek Masterplan"; alas, no copies of this "teaser" currently exist. ~ Hal Erickson, Rovi