“Twilight Zone” was the fourth single by Iron Maiden, released on 2 March 1981 and is the lead single to the 1981 LP Killers. The song did not appear in the original album in February, but was included in the U.S. release in June and the international 1998 remaster. At the time of its release, it was the band’s second-most successful single, peaking at No. 31 in the UK Singles Chart. It is the band’s first single to feature guitarist Adrian Smith. In the 1990 box set, The First Ten Years, it is on the same CD and 12″ vinyl as the previous single, “Women in Uniform”.