Plot Holes: Throughout this episode, Eck (the two-dimensional being) is trying to find his way back to a "time-warp" or "rift" back to his two-dimensional world so that he may pass through it and close it, lest something from our three-dimensional plane "like a bird, or a plane" passes through it on accident, causing spacetime to break and the world to be destroyed. This leaves us all to pose the question: do floating air and dust particles not count as three-dimensional objects?
A comma never actually appeared in the title of this episode until its release on video. It was printed as "Behold, Eck!" on the video box.
Control Voice: (opening narration) Since the first living thing gazed upward through the darkness, man has seldom been content merely to be born, to endure, and to die. With a curious fervor he has struggled to unlock the mysteries of creation and of the world in which he lives. Sometimes he has won. Sometimes he has lost. And sometimes, in the tumbling torrents of space and time, he has brief glimpses of a world he never even dreams.
Eck: (Responding to the question, "how can you communicate" ) I cannot explain. I absorb. I integrate. I know.
Dr. James Stone: (Speaking to his secretary about Eck) Now why should these particular lenses make him visible when nothing else does?
Elizabeth Dunn: Perhaps because they're made from material which came from another world.
Dr. James Stone: What?
Elizabeth Dunn: Meteoric quartz. You said it had unusual refraction indices.
Dr. James Stone: That's it! I'd forgotten. Meteoric quartz. Of course!
George Wilkerson: (Speaking to Dr. James Stone about Eck) Nobody believes me. They think I'm crazy. Well, I'm not! You hear me? I'm not! I tell you, I saw a creature! Something so frightening....
Eck: In my world, nothing can prevail against fire. You could not understand, it is too different, too far removed from anything you could imagine. It is not even a world at all, as you think of it.
Eck: (Speaking to Dr. James Stone & Elizabeth Dunn) Now I can find the opening of the passageway into time. Oh, thank you. I'll remember you both, always.
Control Voice: (closing narration) Paradoxically, man's endless search for knowledge has often plundered his courage and warped his vision, so that he has faced the unknown with terror rather than awe, and probed the darkness with a scream rather than a light. Yet there have always been men who have touched the texture of tomorrow with understanding and courage. Through these men, we may yet touch the stars.
According to The Outer Limits Companion by David J. Schow, this episode is based on the novel Flatland by Edwin Abbot, although Seeleg Lester is quoted as saying "It had no relation to our story other than the idea of a two-dimensional world."