Ep 20. Vis a Vis

Captain Janeway and the crew of the USS Voyager come across a strange alien race known as the Tak Tak while exploring an uncharted planet. The Tak Tak are interested in conducting trade negotiations with Voyager, but due to their unique physiology, they require a representative from Voyager to communicate with them directly, using a device the Tak Tak call a "telepresence suit."

Tom Paris volunteers to don the suit and represent Voyager, but soon after he begins using it, he is abducted by an alien named Steth who possesses the ability to take on the physical appearance and memories of anyone he touches. Steth takes on Tom's appearance and infiltrates Voyager, attempting to steal vital information and technology from the crew. He also takes advantage of Tom's relationships with B'Elanna Torres and Harry Kim, manipulating them for his own gain.

When Voyager realizes that Steth has taken Tom's place, they launch an investigation to discover the truth and rescue their crewmember. In the meantime, the real Tom is trapped in Steth's lair, trying to find a way to escape and get back to Voyager.

As the crew races against time to stop Steth and save Tom, they must also grapple with the question of identity and what it means to be oneself. The episode explores the themes of trust, betrayal, and the importance of having a strong sense of self, even in the face of adversity.

With its complex plot and thought-provoking themes, "Vis a Vis" is a standout episode in the fourth season of Star Trek: Voyager. It showcases the strong character development of the crew and their ability to work together in the face of danger. Fans of science fiction and classic Star Trek will appreciate the intricate storytelling and unexpected plot twists.