Original air date: November 15, 1968
Everyone is staring intently at the view screen. It seems a ship known as the Defiant has gone missing. Everyone can see the faintly green glowing ship, but it's not picking up on any sensor readings. "Fascinating!", says Spock. Kirk decides Chekov, Bones, Spock and himself will beam over and check it out.
They beam aboard the Defiant, each wearing a Hazmat Suit. It looks like everybody's dead, Jim. Seems like the captain of the Defiant was strangled to death by a disgruntled Red Shirt, who is also dead. What's more, this entire ship including the dead crew members are starting to dissolve. And the transporter is on the fritz! Scotty manages to mend it up but says he can take only three at a time. Kirk bravely insists on being the last to beam aboard. Unfortunately, they can't get a fix on him. As Chekov observes, the Defiant disappeared and took the captain with her.
Shortly thereafter, aliens called the Tholians demand that the Enterprise go away. Spock, who is now in command, insists that they will not leave until Kirk is rescued. The Tholians respond by opening fire. Spock, against Bones' suggestion, fires back. The Tholians decide to trap the crew there forever, and reveal that this is a part of space where people tend to go insane.
Chekov and other crew members lose their minds. Kirk is declared dead after attempts to save him have failed. Everyone is going bonkers one by one. Bones is even nastier to Spock than usual, and to make matters worse, the Tholians are building the eponymous web in space using their jetstreams so the Enterprise can't leave.
The Tholian Tropes:
- Beehive Barrier: the Tholians are making a spherical geometric web thing to trap the Enterprise. In this case, the barrier is to keep the Enterprise in.
- Blatant Lies: Spock and Bones flatly deny ever looking at Kirk's Video Will. Kirk doesn't seem to believe them, but plays along.
- Bling of War: Kirk's medal from "This Side of Paradise" makes another appearance.
- Bottle Episode: Takes place entirely on the Enterprise standing sets (doubling for the last time as another Constitution class). While we do get some new effects the Tholian ship is little more than a wooden diamond and the Tholian itself a glove puppet on a screen.
- Conflict Ball: McCoy is exceptionally critical of Spock this episode, even by his usual standards. He says that Spock's first responsibility is to safeguard the crew, implying that they should not be trying to save Captain Kirk. At least some of this is due to the madness-inducing effects of the "interphasic space" Enterprise is currently inhabiting.
- Doctor's Orders: Bones says, "That's a medical order, Captain", when he insists on making a toast with Spock with the antidote.
- Door Jam: Kirk gets stranded in "interspace" with only limited air in his spacesuit, while complications ensue for the rest of the crew.
- Due to the Dead: Spock calls for a moment of silence for Captain Kirk. Bones insists that he and Spock watch Kirk's Video Will. When it reveals that his Last Request is for Bones and Spock to try to get along, Bones apologizes for being Dr. Jerk and they attempt to comply with Kirk's wishes.
- Extremophile Lifeforms: The Tholians are silicon-based bug-like aliens adapted to environments so hot that being subjected to anything lower than 380 Kelvin — about ten degrees above the boiling point of water — will crack their carapace and kill them.
- Fish-Eye Lens: Prominently used right in the beginning as the crazed Chekov's point of view, with a horribly distorted Spock front and center. Chekov screams, naturally.
- Friendship Moment: After Bones apologizes to Spock, Spock replies, "...I believe the Captain would merely have said ... 'Forget it, Bones'".
- Hate Plague: A Negative Space Wedgie drove the crew of the Defiant to kill each other, and then begins to drive the Enterprise crew to outbursts of anger.
- Hyperspeed Escape: An unusual variation for Trek. Spock is able to calculate, combined with the interphasic space and "its" periodic overlaps with "ours," how to apply "ship's power" to alter how it will open, and thus yank Enterprise from "our" space, where she's all but trapped by the Tholian web, to "theirs," where she's free to escape and rescue Kirk.
- I See Them, Too: Scotty, Spock and McCoy know the vision Uhura had of Captain Kirk was real when they see him themselves. McCoy releases Uhura telling her she is all right, "we all saw him, the Captain's still alive."
- If I Do Not Return: Spock and McCoy view the message Kirk left behind for this contingency when Kirk is lost and presumed dead.
- Impairment Shot: The P.O.V. Cam gets a Fish-Eye Lens and jitters when someone's starting to get a little craaaaazy....
- Innocuously Important Episode: Defiant's disappearance into interspace will have major consequences for the Mirror Universe that resonate well into the 24th century.
- Large Ham: It says something about William Shatner that even when Kirk appears as a translucent, inaudible ghost, he still looks like he's chowing down on cold slices of ham.
- Ludicrous Precision: The Tholians attack precisely when the hour is up after the Enterprise was unable to rescue the Captain.Spock: The renowned Tholian punctuality.note
- Kind Restraints: When Chekov goes violently insane due to the effect of the area of space the Enterprise is in, he's shown strapped down to a table in Sick Bay screaming. Uhura is also strapped down after her vision of Captain Kirk, even though she remains very quiet.
- Loafing in Full Costume: Averted. We see Uhura in civvies. She wears a red kaftan-inspired dress and is about to accessorize with a gold necklace when she starts having chest pains.
- Men Are the Expendable Gender: Zig-Zagged. Initially, all of the dead Defiant crew we see are men, playing this trope straight. However, the corpse of a woman can be seen in one of the compartments.
- The Men First: Kirk, Spock, McCoy, and Chekov beam onto the Defiant. When she starts disappearing, Scotty can beam three of them back to the Enterprise because the transporters are acting up, so somebody has to stay behind. Naturally, Kirk chooses himself.
- The Mutiny: Initially suspected, as the first sight they see is the Defiant's captain dead on the bridge with a Red Shirt's corpse grasping his (broken) neck.
- Obvious Stunt Double: During the attacks on both McCoy and Scotty, their stunt doubles take the brunt of the attacks. It's especially evident in 1080p.
- Premature Eulogy: Kirk is presumed dead when he is pulled into another universe. We get an official ceremony with about 50 people present and Spock lamenting his friend—as much as a Vulcan would, anyway. McCoy finishes up by giving another short eulogy in Kirk's quarters during the next scene.Spock: I shall not attempt to voice the quality of respect and admiration that Captain Kirk commanded. Each of you... must evaluate the loss, in the privacy of your own thoughts.
- Russian Guy Suffers Most: Chekov is the first one on the Enterprise to go completely bonkers.
- Space Madness: Being in a particular area of space causes violent insanity by distorting the molecular structure of brain tissues and the central nervous system. Symptoms include dizziness, chest pains and attempting to murder your senior officer.
- Starfish Aliens: The Tholians look like 20-siders with Glowing Eyes. They were, in fact, meant to look like living jewels. They would get a massive effects upgrade (along with the Gorn) when they finally returned in Star Trek: Enterprise.
- The Tape Knew You Would Say That: Kirk's "final orders" assume three things: that he's dead, that the tactical situation is critical, and that Spock and McCoy are at odds. He's right on 2 of the 3.
- Tears of Joy: Uhura sheds a few when she learns that not only is she not crazy, but Kirk is indeed still alive.
- Thin Dimensional Barrier: The crew of the Enterprise accidentally stumbles upon one of these in space while investigating a recently dead Federation ship. Kirk gets trapped in the other universe, while distortions in the laws of physics start to prevent the Enterprise's systems (and the crew's brains) from working properly.
- 2-D Space: Averted. The web appears to be spherical.
- Video Will: Kirk leaves a final set of instructions for Spock and McCoy should he be declared dead.Kirk: Bones, Spock. since you are playing this tape, we will assume that I am dead, that the tactical situation is critical, and both of you are locked in mortal combat. It means, Spock, that you have control of the ship and are probably making the most difficult decisions of your career. I can offer only one small piece of advice, for whatever it's worth. Use every scrap of knowledge and logic you have to save the ship. But temper your judgment with intuitive insight. I believe you have those qualities, but if you can't find them in yourself, seek out McCoy. Ask his advice. And if you find it sound, take it. Bones, you've heard what I've just told Spock. Help him if you can. But remember he is the Captain. His decisions must be followed without question. You might find that he is capable of human insight and human error. They are most difficult to defend, but you will find that he is deserving of the same loyalty and confidence each of you have given me. Take care.
- What Happened to the Mouse?: What happened to the Defiant? Over thirty years later, we find out in the Star Trek: Enterprise Mirror Universe episode "In a Mirror, Darkly".