In the "Cathexis" episode of "Star Trek: Voyager" (Monday, May 1, 8:00-9:00 p.m. et/pt), both Tuvok and Chakotay return from a routine expedition injured - Tuvok with minor ailments and Chakotay grievously injured. It seems that during an encounter with a black nebula, all of Chakotay's neural energy was depleted and unless it is returned in the near future, Chakotay may be doomed to a life as a brain-dead host.
While trying to return to nebula, the crew of Voyager discovers that there is an alien presence aboard that can control their efforts. As the ship nears the nebula, Janeway discovers that the alien has taken over Tuvok all seems lost as he takes command of the ship and they enter the nebula, until the spirit of Chakotay which had been trying to help all along, takes more drastic measures and saves the lives of the Voyager crew.
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 Tom Paris, Robert Picardo as The Doctor, Ethan Phillips as Neelix, Tim Russ as Tuvok, Garrett Wang as Harry Kim.
Story by Brannon Braga & Joe Menosky
Teleplay by Brannon Braga
Directed by Kim Friedman