Archibald Beechcroft hates the crowded modern world, finally working up to expressing the desire to wipe out all of humanity except for himself. Given a book, "The Mind and The Matter," Beechcroft learns the secret of "ultimate concentration." He then decides to apply his concentration to dealing with the existence of everyone else. He begins by concentrating away his irritating lady-lady. "Today, the landlady... tomorrow...the world!"
Encountering a crowded subway platform, he wishes all the people away. The turnstile admits him with a wag of his finger, the train arrives, automated now to make up for the disappeared conductor. The doors to his office even open when he shakes his newspaper at them. The crowded office is silent. He quickly grows bored at work (why is he at work?) and begins talking to himself in reflections. He grows so bored he even triggers an earthquake, and then a storm.
Still talking to himself, he hits upon a solution: remake the population of the world, but in his image. Dyspeptic, anti-social, and constantly muttering, they are all him now, the women too. Played by the same actor and a few unconvincing masks. Beechcroft resigns himself to returning everything to as is was, bored by loniliness and horrified by literal self-loathing.
In many ways an expanded "5,271,009" or a more concise and personal The Lathe Of Heaven or Eye In The Sky. While many people takes away the message of "be careful what you wish for," Serling is, to me, making a more subtle point about the permanent intertwining of utopia and dystopia. They are so intertwined that they are the same thing. There are no perfect societies. Attempting to manufacture them is folly. But, then, I'm not too much on the explicit message that Serling puts in the coda. This is not the best of all possible worlds. Not by a long shot.
The episode could also be read as a rather frightening parable about solipsism. Is Beechcroft actually willing everyone out of existence? Is he a god? Or is he only willing away his perceptions of everyone, and thereby exhibiting an amazing ability to warp his own perceptions, a frighteningly compete control of his flow of subjective reality. Does only Beechcroft have the power? Does everyone have it? (The young man who gives Beechcroft the book relates an incident where he displayed powers to bend someone's will to his own.) Or only readers of the book? And what are the doomsday implications of a book that can turn anyone into a wide-awake George Orr? And assuming that Beechcroft's abilities are effecting objective reality and he is not unique, don't we have to wrap our minds around dueling solipsistic narratives struggling to reshape reality?