When someone tries to assassinate diplomat Sir Reginald Styles, UNIT investigate the possibility his attacker came from the future.
Quest roles:
Richard Franklin(Mike Yates), John Scott Martin(Dalek Operator), Nicholas Courtney(Brig. Lethbridge-Stewart), Murphy Grumbar(Dalek Operator), John Levene(Sergeant Benton), Aubrey Woods(Controller), Anna Barry(Anat), Jimmy Winston(Shura), Scott Fredericks(Maximillian Stael), Wilfred Carter(Sir Reginald Styles), Deborah Brayshaw(Girl Technician), Tim Condren(Guerilla), Rick Lester(Third Ogron), Maurice Bush(Ogron), Ricky Newby(Dalek), Peter Messaline(Dalek Voices (voice)), Sarah Kemp(UNIT Radio Operator), Jean MacFarlane(Miss Paget), Oliver Gilbert(Dalek Voices (voice))