Star Trek (1966–1969)
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The Immunity Syndrome 

The Enterprise encounters a gigantic energy draining space organism that threatens the galaxy.



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Episode complete credited cast:
John Winston ...


The Enterprise is sent to investigate the disruption of the Gamma VII-A solar system and the destruction of the U.S.S. Intrepid, staffed solely by Vulcans. When they arrive they find a large dark mass floating in space that is draining energy from everything around it, including the Enterprise. Drawn into the mass, they find a huge amoeba-like creature and Kirk must decide which of his two friends, McCoy or Spock, to send into it aboard a shuttle craft on a mission of no return. Written by garykmcd

Plot Summary | Plot Synopsis


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Release Date:

19 January 1968 (USA)  »

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Technical Specs


Sound Mix:


Aspect Ratio:

1.33 : 1
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Did You Know?


The usual banter between Spock and McCoy takes on an uncharacteristically dark tone as Spock is preparing to board the shuttlecraft. His exhausted condition obviously affecting his behavior,, McCoy accuses Spock of ambition and spite. "You're determined not to let me share in this, aren't you?".Had he been thinking more clearly, he would have realized Vulcans do not act on ambition or spite.. See more »


The shuttle used is the Galileo. The Galileo was destroyed at the end of, "The Galileo Seven", from season one. See more »


Capt. Kirk: Captain's Log, stardate 4307.1. Approaching Starbase 6 for a much-needed period of rest and recreation. The crew has performed excellently, but is exhausted, and I, too, am looking forward to a nice period of rest on some lovely...
[he watches a pretty yeoman pass his chair]
Capt. Kirk: ... planet.
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Featured in Harlem Theatre (1968) See more »

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User Reviews

good plot; close analogy to the Doomsday Machine
20 September 2007 | by (Canada) – See all my reviews

Its sometimes hard to get excited at fighting a giant amoeba compared to the terrifying looking Doomsday Machine! This show seems to be partly modelled on the previous Doomsday Machine episode where the Enterprise was also engaged in conflict with a creature of immense power that threatens to destroy all life in the galaxy. Unfortunately, there is no Commmodore Decker to bring added excitement to the episode though it was nice to see Spock volunteer to sacrifice himself on a near suicidal mission to save the Enterprise towards the end of the show...shades of the Wrath of Khan. I notice most people rate this episode an 8 out of 10 and I tend to agree. The special effects here are OK for a 1960's show.

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