Day of the Daleks is the first serial of the ninth season of the British science fiction television series Doctor Who, which was first broadcast in four weekly parts from 1 to 22 January 1972. It was the first of four Third Doctor serials to feature the Daleks, which returned to the series for the first time since The Evil of the Daleks (1967). In the serial, the Doctor and UNIT investigate the attempted assassination of British diplomat Sir Reginald Styles, whose attacker apparently disappeared into thin air.