The Silence - S2-E25
Trivia: Midway through shooting, Franchot Tone got into a brawl that left him with facial abrasions on one side so severe they couldn't be covered with make-up. So, in the "glass room" scenes, shots of him are, bizarrely, in profile only or taken from behind barriers obscuring half his face. Some profile shots were reversed to create the illusion that in various takes, we were seeing both sides of him. (00:17:00)
Trivia: When the script called for 6-year-old Billy Mumy's character to be found floating in a fountain full of water, the child actor's mother objected, and the scene was changed. Says Mumy, "I wanted to do it. I was a very good swimmer. But Mom was terrified I'd get some weird ideas about suicide if I did."
The Odyssey of Flight 33 - S2-E18
Trivia: The most expensive footage ever shot for Twilight Zone occurs here, with the stop-motion dinosaur. The 10-second shot cost $2500 - a fortune in 1960 - and didn't even include having to build the model. The "toy" dinosaur was a borrowed prop from the movie Dinosaurus. (00:16:00)
Twenty-Two - S2-E17
Trivia: Barbara's fall on the tarmac wasn't in the script, but they kept it in anyway.
Will the Real Martian Please Stand Up - S2-E28
Trivia: The name of the bus line is Cayuga, which happens to be who The Twilight Zone series was made by, Cayuga Productions, Inc. That company was created by Rod Serling himself.
The Eye of the Beholder - S2-E6
Trivia: When the bandages are finally removed, the beautiful face of Donna Douglas, best known as Ellie May Clampett in the Beverly Hillbillies, is revealed. But the voice while bandaged was provided by Maxine Stewart.
Nick of Time - S2-E7
Trivia: The role of Don S. Carter in this episode was played by a younger William Shatner, who is better known as the famous Captain James T. Kirk in Star Trek. He also starred as the main character in S5: Ep3, "Nightmare at 20,000 Feet."
Answer: It's explained in the episode. The aliens are experimenting to see how humans react to various scenarios. This just happens to involve them using super strength.
Thanks. It's been a long time since I saw the episode so I forgot.