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:
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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 final bit of Kirk looking at a crew woman and repeating his line about hoping to "get some rest on some lovely... planet" was not in the script. It was added by William Shatner and director Joseph Pevney during filming. See more »


When McCoy and Spock leave the bridge after Spock's near-collapse in the opening scene, Kyle, at the helm, is wearing a red shirt. McCoy gives Spock an examination, but does not confine him to Sickbay, so we can surmise that Spock is only off the bridge for a couple of hours at the most. When he returns, Kyle is wearing a gold shirt. See more »


Christine Chapel: Doctor, they seem to be stabilizing.
Dr. McCoy: But at a dangerously low level. Well, we're still alive. I suppose that's something.
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Referenced in Star Wars: Episode IV - A New Hope (1977) See more »

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User Reviews

The Enterprise vs. a very Huge Cosmic Germ
19 November 2006 | by (United States) – See all my reviews

It's a cosmic threat to the galaxy which the Enterprise crew faces this time, an unusual invader, to say the least (see the previous season's "Operation Annihilate!" for another far-out invader). This episode gains a point or two for the almost mind-blowing observation, voiced by Kirk & McCoy, that mankind's sole destiny may be in repelling such invaders of our galaxy; our species may, in this theory, act like antibodies of the galaxy-body, fending off invading cosmic viruses. As the story begins, we're too late to save a solar system and one starship, manned by Vulcans, has also fallen victim to the invader, a one-celled organism about 11,000 miles long, surrounded by some black nega-field. Conceivably, were this creature to reproduce, as the crew discovers it is about to, it would eventually fill the entire galaxy. Pretty wild. The pace is a bit slow in this episode, sort of reflecting the lethargy the crew becomes afflicted with - the space creature drains energy, including the life functions of human beings.

Much of the tension in the story stems from the rather strange competition developing between Spock and McCoy. Both seem a little too eager to be the one to pilot a shuttlecraft into the gelatinous mass of the creature and conduct analysis, even though this little mission is regarded as a one-way trip, a suicide mission. Kirk has to pick one of them for the trip and, though Spock accuses McCoy of having a martyr complex, they both hint to Kirk, 'pick me! pick me to die!' in the same fashion. This episode takes the often-volatile Spock-McCoy relationship to the next level, binding them together in an odd death wish syndrome. Whether they're both attempting to impress Kirk or seeking to discover new scientific concepts, their efforts to outdo each other is taken to ludicrous levels here, as it boils down to which one wants to die more. I also got the uneasy impression that certain men join a service such as Starfleet to escape normal life with the goal of giving up their own in a glorious pursuit of the fantastic, like walking barefoot into a live volcano on the chance they'd learn something no one else knows.

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