"Symbiogenesis" - A bizarre occurrence causes Neelix and Tuvok, who are attempting to transport back to Voyager from an away mission, to arrive aboard ship as one. The crew is astonished when a strange but oddly familiar alien humanoid with dark speckled skin and pointy ears - which is neither Tuvok or Neelix - appears. The Doctor's bio-scanner shows that the Neelix and Tuvok's patterns have merged, causing the pair to become one entity - Tuvix - a humor-filled, logic defying fusion of the two crewmen on "Star Trek: Voyager" airing MONDAY, MAY 6 (8:00-9:00 p.m., ET/PT) on UPN.
While Tuvix assimilates and starts to become a valued member of the team, Kes struggles with the fact Neelix may not be part of her life anymore. Meanwhile, The Doctor devises a method to restore Tuvok and Neelix, except for one variable - Tuvix doesn't want to die. When The Doctor, who is programmed to follow certain ethical guidelines, cannot perform the the separation, Janeway is left with a monumental decision.
Starring Kate Mulgrew as Captain Janeway, Robert Beltran as Chakotay, Roxann Biggs-Dawson as B'Elanna Torres, Jennifer Lien as Kes, Robert Duncan McNeill as Lt. Tom Paris, Ethan Phillips as Neelix, Robert Picardo as The Doctor, Tim Russ as Tuvok, Garrett Wang as Harry Kim.
Guest starring are Tom Wright as Tuvix, Simon Billig as Hogan and Bahni Turpin as Swinn.
The story was written by Andrew Price and Mark Gaberman and the teleplay was written by Kenneth Biller. The episode was directed by Cliff Bole.