TOS: S1 – E25: Devil in the Dark

To many Trek fans, this is the one where Spock mind-melds with a walking lasagna. Yes, really. Devil in the Dark is an iconic story of understanding, where the deaths of miners created an opportunity for Kirk and the others to understand a new life, but not as we know it.

STARDATE: 3196.1

The episode begins with a group of orange-clad, New York-accented miners talking about a monster, which had killed six of their comrades. As soon as one was left by himself, he was “burned to a crisp.”

NOTE: These uniforms appear to be the same thing that Zefram Cochrane wore in the The Original Series second season episode, Metamorphosis.

“Spock, we seem to have been given a choice — death by asphyxiation or death by radiation poisoning,” said Kirk.

The Enterprise arrived on Janus VI, after responding to the distress signal from the men at the pergium mining colony. Kirk, Spock, and McCoy beamed down to chat with Chief Engineer Vanderberg (Ken Lynch).

NOTE: We learn later that “pergium” is a uranium-like ore, which fuels power plants on planets throughout the galaxy. You’d think by the 23rd Century; they’d have cold fusion or highly-efficient solar in use on these planets. 

Vanderberg said the attacks started when the men opened up a new line, but problems began like parts of machines being disintegrated. When workers went to fix the damaged devices, they would be found later “seared.”

McCoy asked to examine the body, and he left to look it over. Kirk spoke with the chief processing engineer Ed Appel (Brad Weston), who claimed to have seen the “monster.” Appell could not describe it other than “shaggy,” but said that he shot it with a phaser, but it survived. 

Vanderberg said that mining had stopped until the problem was solved. Kirk asked for a complete map of the mines; Vanderberg agreed to give him one. Spock lifted a sphere from Vanderberg’s desk and asked what it was. Vanderberg said that it was a silicon nodule.

“At least, not life as we know it,” said Spock.

“There are a million down there,” Vanderberg said. “They have no commercial value.”

Spock said it was a geological oddity. Vanderberg got upset with Spock’s questions about the nodules. Kirk asked for Vanderberg’s cooperation. He agreed and told Kirk to find the creature as he had a quota to beat.

McCoy returned and said the man did not burn; he died from chemical corrosion. He added that these chemicals were strong enough to eat at machines or anything else.

Spock said there was no other life than human activity. He then added:

“At least, not life as we know it,” said Spock. Kirk said they had to restart the production of pergium. Vanderberg warned that when men are down in the tunnels — they die.

NOTE: Ah! This would be a classic Spock line, used several more times, but it gained particular notoriety in The Firm’s silly song, “Star Trekkin’.

Later, another miner was killed, and all that was left was a burnt spot on the ground. The creature also left a large hole in the wall to the reactor room. Kirk, Spock, McCoy, and Vanderberg ran to the reactor room, phasers drawn. 

Spock said an extremely active corrosive ate through the walls. Vanderberg announced that the circulating pump for the reactor had been taken. He said that soon all life support would go out.

Kirk with Chief Engineer Vanderberg (Ken Lynch), and Spock. Courtesy of CBS / Paramount
Kirk with Chief Engineer Vanderberg (Ken Lynch), and Spock. Courtesy of CBS / Paramount

“Spock, we seem to have been given a choice — death by asphyxiation or death by radiation poisoning,” said Kirk.

Kirk asked Scotty to rig up something to replace the pump. Kirk told Vanderberg that they might have to evacuate all his men, but they needed the pergium to power reactors on other worlds.

Later, Spock said that the pump had been taken deliberately. Kirk supposed that the creature is trying to push the colonists off the planet. Kirk wondered why this was happening now since the facility had been in operation for over 50 years. 

Spock said there might be a possible life form, which was silicon-based. Kirk agreed. Spock noted the Phaser I model might not be powerful enough to penetrate the monster’s armor. Spock said he could modify a Phaser II to work against silicon. 

“Silicon life is physiologically impossible, especially in an oxygen atmosphere,” said McCoy. 

Kirk ordered that Spock modify some phasers, and send an Enterprise security team down to the tunnels on patrol. 

Spock stared at the silicon nodule sphere and noted that Vanderberg said they found these everywhere on a new lower level. Spock also pointed out that this lower tunnel was opened up right before the attacks occurred. 

Spock and Kirk in the tunnels
Spock and Kirk in the tunnels. Courtesy of CBS / Paramount

Scotty beamed down and began working on the pump. Kirk ordered the “redshirts” to go to all levels looking for the creature, starting on the 23rd level (the new tunnels). 

NOTE: The shot of Kirk with his security team became a popular image for memes as if Kirk was sending this group to their deaths. 

As they all fanned out, the creature killed one of the security personnel. Spock and Kirk only found his smoking shape. Spock found a brand new tunnel “as far as the eye can see.” 

As they looked over the new tunnel, an animal of some kind appeared behind them. The creature looked like a giant, pulsating Chicago deep-dish pizza, with a marshmallow glaze. Kirk fired, and it retreated into a tunnel. 

Other ship’s security personnel arrived as Spock inspected the hunk of the creature that Kirk dislodged with his phaser fire. It was still pulsating. Spock said it was “fibrous asbestos.” Spock was correct that the creature was a silicon-based life form.

Kirk and Spock give the creature a bit of pain. Courtesy of CBS / Paramount
Kirk and Spock give the creature a bit of pain. Courtesy of CBS / Paramount

“We are dealing with a silicon creature of the deep rocks,” Spock said. “Capable of moving through solid rock as we move through the air.” 

Kirk surmised that it could be killed by a more prolonged or more powerful phaser blast. He warned his men.

“There’s nothing more dangerous than a wounded animal,” said the captain.

Spock used his tricorder to detect the creature — but only one. He said that they must not kill the creature because that would be a crime against science. 

Kirk said that he was sorry, but the creature must be killed. Spock agreed.

“The odds against you and I both being killed are 2,228.7 to one,” said Spock.

Spock gathered the team and told them to aim for the “head.” Spock told them where it probably was. Spock said they should try to surround it and capture it. 

Kirk looked up, and he ordered them to “shoot to kill.” He lectured Spock and said there would be no more deaths, and they would not try to capture the creature. He then tried to reassign Spock to help Scotty on the pump, reasoning that the creature in the hunt could kill them both. Spock disagreed.

“The odds against you and I both being killed are 2,228.7 to one,” said Spock.

Scotty called to say that his pump failed, and they had 10 hours to find the part for the reactor before it goes super-critical. Kirk ordered the immediate evacuation of the colony. Vanderberg said that some of his men would stay behind. Kirk split them up into teams with his crew.

Spock said they were being watched. He and Kirk split up and went into different tunnels in pursuit of the creature. At the end of the tunnel Kirk chose, he found hundreds of silicon nodules. He called to Spock, who told him not to damage any of them. Just then, the creature caused a minor cave-in. 

As Kirk watched, the creature bore threw a cave wall and approached him. When he raised his phaser, it stopped. When he lowered it, the creature came at him once more. 

Spock called Kirk and told him to kill the creature. Spock told him to kill the creature, but Kirk wouldn’t. Spock rushed to get there.

Kirk sat and started talking to the creature and noticed the wound. Spock arrived, and Kirk told him not to shoot. Spock sat next to Kirk and proposed a mind-meld. Kirk approved.

Spock melding
Spock mind-melding with the Horta. Courtesy of CBS / Paramount

Before Spock could even touch the creature, he yelled out that he felt only pain. The creature then used its acid to burn words into the rock — “NO KILL I.” 

 Spock said that while they were joined, he learned that it was a highly intelligent creature, and it called itself a “Horta.” Kirk asked that Spock ask it to return the part for the pump. Spock said that the Horta had no reason to help. Kirk wondered if there was any way to get the Horta’s confidence. 

NOTE: The stuntman and actor Janos Prohaska, who also performed as the Mugato in “A Private Little War,” another TOS S2 episode, played the Horta. 

Kirk ordered McCoy to come down to the tunnel, and that the doctor had a new patient. 

Spock then touched the Horta and melded with it. While that was happening, Kirk contacted Security Chief Giotto (Barry Russo), who said that Vanderberg and his men wanted to come to the end of the tunnel. Kirk ordered him to keep the miners put, but to allow McCoy through.

As he continued the meld, Spock screamed out several times with messages like “murderers” and “devils” about the miners. 

McCoy walked up and was shocked to see the Horta and Spock hunched over it. He asked what Spock was doing, but Kirk ordered the doctor to do what he could for the Horta. McCoy asked Kirk again what he was supposed to do with the Horta. He said it’s basically stone.

“I’m a doctor, not a bricklayer!” said McCoy. Kirk ordered McCoy to help. Kirk asked Spock to tell the Horta that it was trying to help, and also to ask for the creature to give them the location of the needed part.

“The end of life… eternity stops… go out into the tunnel to the chamber of the ages,” Spock. He wept as he talked about the murdered children. But Spock relayed to Kirk where the part was. 

At the same time, Giotto was struggling to keep the miners in line. They were demanding to kill the creature.

Security Chief Giotto (Barry Russo)
Security Chief Giotto, played by Barry Russo. Courtesy of CBS / Paramount

Kirk found his way through the tunnel and saw an opening full of hundreds of opened silicon nodule spheres. 

While looking at the Horta, McCoy requested a device to be beamed from the Enterprise. Spock continued to relay the messages of the creatures. 

Kirk returned with the missing part and an opened egg. Kirk said that the miners must have opened up that area and smashed hundreds of unhatched eggs. 

Meanwhile, the miners overwhelmed the security detail and ran to where the Horta was (as McCoy was working on it). The shouted and pointed — saying that they wanted to kill the Horta. 

“The first man who fires is dead,” said Kirk. 

They argued that 50 men were dead due to the Horta. Kirk said that the men killed thousands of her babies. He told them that all of the nodules they destroyed were her eggs. Spock explained that every 50,000 years, the Horta all die except for one, which lays thousands of eggs and cares for them.

NOTE: In a way, this Kirk and Spock were ensuring that we’d have Horta: The Next Generation.

Vanderberg said they did not know what they were doing, but asked what would happen when the eggs hatch. One of his men said that they also had pergium to deliver.

Kirk returned the pump and suggested that the men could work with the Horta to tunnel, and the men would collect the minerals they want. Vanderberg said it sounded good.

Spock said to hold on — the Horta might die. McCoy said that she would not die.

Doctor McCoy
Doctor McCoy figured out a way to heal a silicon-base patient. Courtesy of CBS / Paramount

“By golly, Jim — I’m beginning to think that I can cure a rainy day!” McCoy said, his hands covered in wet thermo-concrete. 

Kirk asked the Horta if she was feeling better and if she would agree to this arrangement. Spock said it should, as the Horta is a very logical being.

Before the Enterprise left, Vanderberg called to Kirk to say that the eggs were hatching and that they have found substantial new deposits of pergium. They also found silver, gold, and rare earth elements.

Vanderberg said that the Horta aren’t so bad, once you get used to their appearance. Spock said that the Horta said the same about humans. 


What a great show! It was suspenseful, action-packed, and full of mystery. The underlying message was very hopeful and was one that we could all learn from — even fifty-some years after its original airing. There are things we humans can learn from all creatures… sometimes we just can’t hear them. 

RATING: 5 out of 5


Directed by: Joseph Peveny
Written and Produced by: Gene L. Coon
Executive Producer: Gene Roddenberry
Associate Producer: Robert H. Justman
Music composed and conducted by: Alexander Courage
Script Consultant: D.C. Fontana
Director of Photography: Jerry Finnerman
Art Directors: Roland M. Brooks and Walter M. Jeffries


William Shatner as Kirk
Leonard Nimoy as Spock

DeForest Kelley … as Dr. McCoy
Ken Lynch … as Vandenberg


James Doohan … as Scott
Brad Weston … as Appel
Biff Elliot … as Schmitter
George E. Allen … as Engineer #1
Jon Cavett … as Engineer #2
Barry Russo … as Giatto

Film Editor … Fabien Torjmamm
Assistant to the Producer … Edward K. Milkis
Assistant Director … Gregg Peters
Set Decorator … Marvin March
Costumes created by … William Theiss

Post Production Executive … Bill Heath
Music Editor … Jim Henrikson
Sound Editor … Douglas H. Grindstaff
Sound Mixer … Carl W. Daniels
Photographic Effects … Film Effects of Hollywood
Script Supervisor … George A. Rutter
Music Consultant … Wilbur Hatch
Music Coordinator … Julian Davidson
Special Effects … Jim Rugg
Property Master … Irving A. Feinberg
Gaffer … George H. Merhoff
Head Grip … George Rader
Production Supervisor … Bernard A. Windin
Makeup Artist … Fred B. Phillips, S.M.A.
Hair Styles by … Virginia Darcy, C.H.S.
Wardrobe Mistress … Margaret Makau
Casting … Joseph D’Agosta
Sound … Glen Glenn Sound Co.

A DesiLu Production in association with the Norway Company

Executive in Charge of Production … Herbert F. Solow