Noncorporeal aliens inhabit the bodies of Enterprise crew members to study how the crew reacts to a lethal virus infection that has afflicted Trip and Hoshi.


(as Mike Vejar)


(based upon "Star Trek" created by), (created by) | 3 more credits »

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Trip and Hoshi are returning from a visit to a planet where the Klingons once landed. Nothing interesting could be found, but in the shuttle pod back Trip suddenly starts coughing. A while later he collapses. Dr. Phlox finds out they are infected by a silicon-based virus. He estimates that the pathogen will kill them in five hours. Meanwhile an alien species seems to have taken over Mayweather and Reed. They are discussing the behavior of the Humans. For 10000 years they have been observing the reactions to the viruses to measure the intelligence of the infected species. Will the crew surprise them? Written by Arnoud Tiele (

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Release Date:

21 January 2005 (USA)  »

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Did You Know?


When trying to break the lock-out code of the decon chamber, Hoshi says that math is just another language. With that, she repeats the same opinion T'Pol has once voiced in Star Trek: Enterprise: Vox Sola (2002), when Hoshi was struggling with the equations of an alien language. The fact that she succeeds in this instance shows that she has evidently mastered the "language" of math in the meantime. See more »


[first lines]
["Reed" and "Mayweather" are playing chess]
Alien inhabiting Ens. Mayweather: You win in eight moves.
Alien inhabiting Lt. Reed: You're really starting to get a feel for the game.
Alien inhabiting Ens. Mayweather: 32 pieces, 64 squares - it's not as if it's difficult. Total number of possible outcomes is limited.
Alien inhabiting Lt. Reed: Ten to the 123rd power.
Alien inhabiting Ens. Mayweather: That's what I mean. Chess is so predictable. I'm surprised anyone bothers to play it.
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References Star Trek: Enterprise: Vox Sola (2002) See more »


Archer's Theme [Enterprise - Music from the Original Television Soundtrack]
Written by Dennis McCarthy
Performed by Dennis McCarthy
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User Reviews

One of the better ones.
30 May 2015 | by (Bradenton, Florida) – See all my reviews

This is a very interesting episode of "Star Trek: Enterprise". A couple beings without corporeal bodies have entered the ship and are able to inhabit the bodies of crew members. The possessed do not know this is occurring nor do they have memories of it. The pair are investigating new species and how they deal with a problem. It seems that there is a horribly virulent disease that various humanoids contract in this part of space...and they want to see how these humans deal with it. Interestingly, these beings think they are amazingly advanced...but they also have an amazingly ambivalent view of folks who are dying. However, over the course of the show, one of them begins to feel come empathy and how this all plays out is for you to see when you see the show.

The best thing about this show is the writing. The idea of ethereal beings occupying folks isn't exactly new--but why and what they do, THAT is very interesting. See this one.

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