Episode Trivia


Originally Spock claims that any ship movement or energy usage will disrupt local space, and the Tholians' arrival is why they can't beam Kirk on board the first time. But...doesn't all of the Tholian movement, the spinning of their Web, etc., disturb space and mess up Enterprise's beaming in Kirk the second time as well? Instead, all of the activity doesn't mess up the second "window of opportunity" at all.
Again, by indications here there is only one person-transporter on the ship - Scotty says he can only get three frequencies working.
When the Tholians attack and McCoy and Chapel throw themselves around to simulate the impact, the bottles in the background stay perfectly still.
Although he hedges the truth several times throughout the series, in this episode Spock quite blatantly lies to Kirk, despite the "Vulcans never lie" thing.
You can see the stars through the back end of the Tholian ship after the Enterprise hits it with phasers.
As in "Spectre of the Gun," we get the idea that Scotty is going to take a bottle of alcohol and start drinking heavily in the middle of a life-or-death crisis.
Although the Defiant and its crew are supposedly fading out of reality (McCoy passes his hand through a table and a crewman), the landing party has no problem walking on the floor.
This episode served as the basis for the "Star Trek: Enterprise" two-part episode "In a Mirror, Darkly, Part I" and "In a Mirror, Darkly, Part II".
In "In a Mirror, Darkly, Part II", it is revealed that the Tholians from the 22nd century mirror universe attempted to snare future technology by trapping a ship in an interspace field that would cause mass insanity among the crew, causing them to kill each other, leaving the ship ripe for capture, and then drawing it into their universe, which is exactly what happened to the U.S.S. Defiant in this episode and nearly to the Enterprise as well.
Dr. McCoy's diagnosis that the Defiant captain's neck is broken would later be repeated by T'Pol in "In a Mirror, Darkly, Part I".
First appearance of the Tholians, although, they would not be seen in the flesh again until "In a Mirror, Darkly, Part I".