Greeting Steed after his three-week vacation, Tara asks him if he enjoyed himself. Unfortunately, he can't say, because he has absolutely no memory of the past three weeks. Investigating this curious lapse of memory, Tara stumbles upon a plot to kill Mother -- with Steed in the thick of things. The episode's highlight is a battle of one-upsmanship between a captive Tara and glamorous-but-deadly enemy agent Lisa (Kate O'Mara). Written by Don Chaffey, "Stay Tuned" first aired in England on February 26, 1969, two days after its American TV premiere. ~ Hal Erickson, Rovi