The Host (TNG)

Star Trek: The Next Generation, Series 4, Episode 23. First broadcast on Monday 13 May 1991. Stardate: 44821.3. Star Trek: The Next Generation makes another ill-judged attempt at romance this week, as Beverly Crusher has an eventful two-week relationship with an alien ambassador, Commander Riker, and an attractive young woman, who are all somehow the same person. It all goes as well as you would expect in a series where every episode returns reliably to the status quo before the credits roll. (Warning: after the closing credits, there are some incidental spoilers for Strange New Worlds Series 2, Episode 7, Those Old Scientists.)