The boy goes on to mention that in a comic book that he read, only the aliens sent down before the spacecraft would be able to leave the town and that they would look and act just like one of them (humans). I would personally find this idea a farce, but the neighborhood entertains this idea after a man disappears to investigate the next block over and doesn't return for hours. At this point, mass hysteria begins to take hold.
The neighborhood becomes suspicious of their neighbors and begins to ostracize one another to figure out who the invaders are. When one neighbors car starts on its own, the mob is quick to question why his car works but theirs don't. Another neighbor points out that she often sees the man standing out in his yard late at night, gazing up into the sky as if he were looking for something. Accusations continue to be passed around, with each neighbor pointing out something suspicious about the other.
Are we beginning to see the theme here? As night falls, paranoia has taken over. Though some might argue that it would likely take more than one day for neighbors to act so rashly, its easy to e that in this confusion of an inexplicable event how effectively The Twilight Zone fast-forwards the like-minded mob mentality to communicate the episode's message. A figure appears in the street, and one man--thinking it to be some sort of invader-?raises a gun and kills the figure for all the mob to see.
It's revealed to us that the figure was no monster at all, just the innocent neighbor that went to investigate the other blocks only couple of hours earlier. At this point, the mob accuses the man who shot their neighbor that he's the real monster-?maybe he wanted them dead all along. They throw stones at him and more chaos ensues. At the end of the episode the camera pans out to a spacecraft perched on a hill overlooking the neighborhood. Two aliens look on as the neighborhood rips itself apart.
They discuss how easily man can be manipulated when you take away their technology and how quickly they turn on one other in times of great panic. The episode concludes with them mentioning how easy it will be to conquer the species with this knowledge in hand. Personally I think The Twilight Zone did an excellent job of showcasing how quickly we can turn on one another in times of crisis. In my own experience with the military, I've been in several situations where something went wrong and people began looking for others to blame.