Thanks to a molecular mix-up, Samantha and her friend, Louise Tate, exchange personalities. As Dr. Bombay seeks out a remedy (involving the marrow from a tiger's tooth), Sam endeavors to save Louise and Larry's marriage. The brief scene in which Elizabeth Montgomery (Sam) chastely shares a bed with David White (Larry) should amuse those viewers who can recall that 1960 episode of The Untouchables, wherein Montgomery played White's flashy mistress. First telecast on March 4, 1971, "Mixed Doubles" was written by Richard Baer. ~ Hal Erickson, Rovi