"Tuvix" is the 40th episode (24th in the second season) of the science fiction television program Star Trek: Voyager. The episode originally aired on May 6, 1996, and tells the story of Tuvok and Neelix being merged into a unique third character named Tuvix.The episode was substantially rewritten from its original incarnation as a silly, lighthearted story to a more somber tale with serious moral and ethical implications.