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When one looks in the box, whatever remains, however improbable, must be the cat.

Reactor

“The Immunity Syndrome”
Written by Robert Sabaroff
Directed by Joseph Pevney
Season 2, Episode 19
Production episode 60348
Original air date: January 19, 1968
Stardate: 4307.1

Captain’s log. While en route to Starbase 6 for some desperately needed R&R, Uhura gets a static-filled message from Starbase 6, with only the words “Intrepid” and a set of coordinates. The Intrepid is a ship entirely staffed by Vulcans. While Uhura tries to raise the starbase, Spock becomes overwhelmed—he has telepathically felt the entire crew of the Intrepid die.

As McCoy takes Spock to sickbay, Uhura gets through to the starbase. The Enterprise is ordered to the Gamma VII system, which the Intrepid was investigating. They’ve lost all contact with the Intrepid. Chekov does a long-range scan, only to find that the system—which is inhabited with a thriving star—is completely dead.

Star Trek the Original Series, season 2, The Immunity Syndrome

McCoy examines Spock and finds nothing wrong. The pain was momentary, but he definitely felt all four hundred Vulcans on the Intrepid die. He returns to duty just as they arrive at Gamma VII. Uhura has lost all contact with the starbase because of the interference, which seems to be coming from an energy reading Spock can’t analyze. It looks like a hole in space where the system (and the Intrepid) should be.

Kirk has Chekov launch a probe, but a loud noise blares through the ship and destroys the probe. But Uhura almost faints, Chekov seems dizzy, and McCoy reports that half the crew has fainted and is suddenly cranky and dizzy and irritable. And the crew was already exhausted going into this mission, that’s why they were headed for R&R.

Star Trek the Original Series, season 2, The Immunity Syndrome

Spock has insufficient data for analysis. It is neither solid, liquid, nor gas, but it did activate the deflectors, so it must be some kind of energy, but not one that the computer recognizes.

Kirk has Kyle approach the zone of darkness, and then the noise comes back. After a few moments, the noise stops—but then the stars disappear. Somehow they have entered the zone of darkness despite not moving. However, they lost five percent of their energy reserves, and Scotty has no idea how or why. McCoy reports that two thirds of the crew is being affected by whatever is making people faint. He and Chapel apply stimulants to the crew.

Star Trek the Original Series, season 2, The Immunity Syndrome

Opening intership, Kirk gives a pep talk to all personnel, hoping to inspire them to do their jobs despite the exhaustion and stuff. Right after that, just to negate the effect of it, McCoy reports that the energy levels of everyone in the crew is dropping—the whole crew is dying. And that same energy drain is affecting the ship.

The ship is being pulled toward the center of the zone of darkness. Scotty tries to apply reverse thrust, and the ship moves forward. Spock suggests applying forward thrust, and Scotty reluctantly does so—and it works! They’re still moving forward, but more slowly.

Star Trek the Original Series, season 2, The Immunity Syndrome

In the briefing room, McCoy reports that the stimulants are helping, but everyone’s still dying. Scotty says that all ship’s functions are working backwards for some reason. Kirk orders Scotty to put all the ship’s power into one big-ass thrust forward in the hopes that it will snap them back out of the zone. Spock also hypothesizes that the zone itself isn’t causing the power drain, but something else inside it.

Spock is concerned that the Intrepid would have done all this stuff, too, but Kirk points out that the sheer illogic of the situation might have vexed the Vulcan crew.

Star Trek the Original Series, season 2, The Immunity Syndrome

Scotty channels all the power into the forward burst, but all it does is allow them to maintain position. At this point, they’ve got two hours of power left.

And then the heart of the zone of darkness reveals itself as it approaches. It looks like a giant space amoeba, and Spock confirms that it’s the source of the energy drain. Chekov launches another probe. Spock reports that it is alive, and it is drawing the Enterprise to its death the same way it drew the Intrepid.

Star Trek the Original Series, season 2, The Immunity Syndrome

McCoy verifies that it is an amoeba—it’s an even simpler life form than the more normal microscopic amoeba they’re used to. They need more information, and the probes can only tell them so much, and they dare not take the ship closer to the amoeba and risk losing power faster.

Both Spock and McCoy recommend taking a shuttlecraft to probe the amoeba and find its vulnerable spots. They also both volunteer to be the pilot, even though it may be a suicide mission. McCoy has already done the preliminary research, and he’s the biology expert; Spock believes he can assess the data more objectively and rationally. Kirk must choose one of them to take on the mission.

Star Trek the Original Series, season 2, The Immunity Syndrome

It’s a difficult, impossible choice, as he must condemn one of his two closest friends to death. Both are qualified, but ultimately he gives it to Spock. McCoy equips the shuttle with everything he’ll need.

Spock penetrates the amoeba’s structure, and determines that it has stored enough energy for reproduction. Spock reduces life support to bare minimum in the hopes of having enough power to get back. Uhura picks up a weak signal from Spock, saying that the amoeba can be destroyed from the inside only, as the outer membrane protects it.

Star Trek the Original Series, season 2, The Immunity Syndrome

Kirk orders Scotty to cut the thrust, and divert all power to shields. He wants the ship to be drawn inside so they can act as an antibody to this amoeba that appears to be a galactic virus. They have to stop it before it reproduces. Since everything seems to work in reverse, Kirk orders Scotty to prepare a magnetic bottle with antimatter, which is the only form of energy this thing is likely not to eat.

After recording a log recommending commendations to McCoy, Scotty, Uhura, Kyle, and Chekov, and a posthumous commendation for Spock, Kirk orders the antimatter bomb to be dropped in the nucleus. It’s on a seven-minute delayed detonation, and Chekov says they’re just over six minutes out.

Star Trek the Original Series, season 2, The Immunity Syndrome

They detect Spock’s shuttle, and despite both Spock and Scotty recommending against it, Kirk orders a tractor beam on the shuttle. Power goes dead, but inertia carries them out of the amoeba’s membrane. The explosion destroys the amoeba, and power is restored to both the Enterprise and the shuttlecraft.

Once the shuttlecraft is back on board, Kirk has Chekov set a course for Starbase 6 for a now really really desperately needed R&R.

Star Trek the Original Series, season 2, The Immunity Syndrome

Can’t we just reverse the polarity? The space amoeba is eleven thousand miles long, width varying from two to three thousand miles, its outer layer is studded with space debris and waste, while the interior consists of protoplasm. That’s a big Twinkie…. 

Fascinating. Though Vulcans are touch telepaths, the death of four hundred can be felt over light-years. Spock also has a rare moment of sentiment, recording a personal log that commends the crew of the Enterprise, calling them the finest crew in the fleet. 

Star Trek the Original Series, season 2, The Immunity Syndrome

I’m a doctor not an escalator. McCoy is eager to be the one to investigate the amoeba as it’s a biological discovery of great value. He’s very cranky about the fact that Spock gets to go instead.

Hailing frequencies open. Uhura has to constantly fight her own dizziness and the interference put out by the amoeba in order to get communications to work.

Star Trek the Original Series, season 2, The Immunity Syndrome

I cannot change the laws of physics! Scotty is his usual can-do self, constantly telling Kirk what a bad idea things are and how badly they can go wrong and such.

It’s a Russian invention. When they penetrate the amoeba, Chekov triumphantly cries, “We’re through, sir!” and Kirk snottily tells him that they’re all aware of that. Give the kid a break, Jim, he was excited! 

Star Trek the Original Series, season 2, The Immunity Syndrome

Ahead warp one, aye. Kyle gets to be the helmsman this time ’round. He wears a gold uniform so the stock footage of the navigation console with Chekov visible on the right and the right arm of the helmsman visible on the left would still work.

No sex, please, we’re Starfleet. Before the shuttle enters the amoeba’s insides, Spock warns, “The area of penetration will no doubt be sensitive.” Wah-HEY! 

Star Trek the Original Series, season 2, The Immunity Syndrome

Channel open. “Captain, I recommend you abandon the attempt. Do not risk the ship further on my behalf.”

“Shut up, Spock, we’re rescuing you!”

“Why thank you—Captain McCoy.”

Spock being all heroic and self-sacrificing and stuff, McCoy snarking him off, and Spock snarking right back.

Welcome aboard. No major guest stars this time ’round, just recurring regulars James Doohan, Nichelle Nichols, Majel Barrett, Walter Koenig, and John Winston.

Star Trek the Original Series, season 2, The Immunity Syndrome

Trivial matters: This is the last time on the series that we see Kirk’s green tunic, the interior of a shuttlecraft, and an episode directed by Joseph Pevney. Pevney was brought in by Gene L. Coon to direct “Arena,” and he became one of the show’s go-to directors (he’s tied with Marc Daniels for most episodes directed). However, Pevney felt the on-set behavior of the actors went south with Coon’s departure, and so he did not come back after this one.

This is Robert Sabaroff’s only script for the original series, but he would be involved in writing two first-season TNG episodes, “Home Soil” and “Conspiracy.”

Star Trek the Original Series, season 2, The Immunity Syndrome

There are a lot of similarities between this episode and the TNG episode “Where Silence Has Lease,” particularly in its first half with holes in space and such.

To boldly go. “Don’t be so smart, Spock, you botched the acetylcholine test!” A surprisingly effective “bottle show,” with no guest stars, no great revelations, but a tense situation that echoes both “The Corbomite Manuever” and “Obsession,” without feeling too terribly similar to either. Although it’s probably best that this didn’t air back to back with “Obsession” originally, as they are both similar enough (non-sentient dangerous creature that is stopped by antimatter). This one comes across far better because the captain doesn’t act like an idiot.

Star Trek the Original Series, season 2, The Immunity Syndrome

This story does reveal a pattern in this second season, though, and it’s not a great one. The first season was impressive because there were very few true monsters. The evil destroying lizards of “Arena” turned out to be a proud species of people known as the Gorn who were just defending themselves. The evil acid-spewing creature that killed the miners in “The Devil in the Dark” turned out to be a mother protecting her young. The big-ass ship with the ugly guy running that endangered the ship in “The Corbomite Maneuver” turned out to be a very weird first contact. Even the salt vampire of “The Man Trap” had an element of tragedy about it as the last of its kind. Trelane was just a kid playing with his toys, Charlie was just a kid who wanted to be loved, Kodos/Karidian was a monster and now is an old man trying to put his past behind him, the planet isn’t trying to kill them but is rather an amusement park, and so on.

This season, though, has had less of the redemptive and compassionate aspect. We still have it in places like “Friday’s Child” and especially “Metamorphosis.” But the evil energy creature who kills people in “Wolf in the Fold” is really an evil energy creature who kills people. The big thing that kills planets in “The Doomsday Machine” is really a big thing that kills planets. The cloud creature that sucks out people’s blood in “Obsession” is really a cloud creature that sucks out people’s blood. And the big-ass space amoeba that sucks energy here is just a big-ass space amoeba that sucks energy. And in all four cases, the Enterprise‘s mission is to destroy it, which is significantly less interesting than learning about it.

Star Trek the Original Series, season 2, The Immunity Syndrome

It’s only disappointing insofar as it reduces the bad guys to just monsters, moving away from the humanistic elements that made Star Trek stand out in the first place.

Having said all that, it works here, especially since the amoeba is just that—the simplest possible life form, albeit with a pituitary problem. There’s no real chance of it being intelligent, and it starts with destroying a starship and an inhabited solar system. It’s definitely something that needs to be stopped before it can reproduce.

Star Trek the Original Series, season 2, The Immunity Syndrome

Several elements make this episode work beautifully. For starters, the crew’s exhaustion adds to the tension—both Kirk’s no-please-we-want-to-go-on-shore-leave-we’re-pooped pleading at the top of the episode combined with the amoeba draining their energy adds a miasma of fatigue to the proceedings. Notably, though, at no point does it compromise anyone’s ability to do their job. Twice the crew is referred to as the finest crew in the fleet, and no better evidence of that can be provided than the fact that they all stay at their posts and do their jobs superlatively even with all this crap being thrown at them.

And then there’s the Kirk-Spock-McCoy triad, which is at its finest here. McCoy’s enthusiasm for going on the shuttle mission and his resentment at Spock is beautifully played by DeForest Kelley, while Leonard Nimoy’s reserved snottiness is pretty much on overdrive. But you also see the underlying respect and affection they both have for each other (something less in evidence in places like “Bread and Circuses” and “The Gamesters of Triskelion,” which both could’ve used it).

Star Trek the Original Series, season 2, The Immunity Syndrome

Finally, William Shatner does a really good job as the leader of all this. His agonizing over the decision of who to send is palpable, but his choice is really the only right one, as the mission truly does require someone who can remain calm and who has greater physical stamina.

 

Warp factor rating: 7

Next week:A Piece of the Action

Keith R.A. DeCandido just finished writing The Warriors Three: Godhood’s End, the third book in his Marvel’s Tales of Asgard trilogy. The first book, Thor: Dueling with Giants is available as an eBook, with the print book due this month; the second book, Sif: Even Dragons Have Their Endings, is available for preorder now.

About the Author

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Keith R.A. DeCandido

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Keith R.A. DeCandido has been writing about popular culture for this site since 2011, primarily but not exclusively writing about Star Trek and screen adaptations of superhero comics. He is also the author of more than 60 novels, more than 100 short stories, and around 50 comic books, both in a variety of licensed universes from Alien to Zorro, as well as in worlds of his own creation. Read his blog, follow him on Facebook, The Site Formerly Known As Twitter, Instagram, Threads, and Blue Sky, and follow him on YouTube and Patreon.
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