3rd Rock from the Sun

A Dick Replacement (6x11)

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Dick and Mary visit Rita, a psychic, together, and Dick scoffs that the whole thing's a rip-off—until the psychic says that Dick and Mary are from two different worlds. She adds that one of these days Dick will leave Mary and go back where he came from. Dick immediately decides that he should devote himself to locating his successor, someone worthy who will wait in the wings until Dick has gone. Later, Sally tells Harry that if the psychic talked about Dick's leaving the planet, she must know they're aliens; they have to kill her. Dick takes Mary to a singles bar in search of the perfect replacement, but he acts so strangely that the bartender thinks Mary's a hooker and asks them to leave. Harry and Sally set about hatching wildly unrealistic plots designed to do away with the psychic. Nina tells Dick about Gary Hemmings, a visiting lecturer who's dying to substitute for him. Dick talks with Gary and offers him the chance to replace him; Gary thinks he's being offered a staff position