An early spot by the great John Astin (soon to become famous as Gomez Addams from "The Addams Family"), playing Charlie, one of Mr. Horn's compatriots, briefly reveals Astin's abilities as a serious character actor as he expresses reserved support for Mr. Horn's dogged persistence. As suggested by this episode's title, upon reaching the other side of the rim, Mr. Horn immediately, but unknowingly enters The Twilight Zone. With wits and courage backed by a quiet, wary intelligence, he begins to understand that which cannot often be grasped through one's ordinary perceptive mechanisms.
In another twist of characterizations, Ed Platt, best remembered for his rare (but long-running) comedic role as Maxwell Smart's (Don Adams) beleaguered, beloved Chief in "Get Smart" beginning four years later, plays his more typical character role here. He portrays the local doc who tries to assist a friendly café owner and his nurturing wife with the unexpected handful of a tattered man who arrives unceremoniously, and bewildered, on their doorstep. How that happened and what follows is unexpected, heartening, and ultimately fascinating in ways that typify "The Twilight Zone" at its best.
And it would be an error of omission not mention the power of the musical score, sometimes subtle, but pounding dramatically toward the climax, just before shifting musical gears once again, precisely on cue. The compositional phrasing provides an effective musical conduit through which the story-line best evokes its emotive content before transitioning back to a perfectly executed return to the introductory setting--except for it having now been duly altered by the Zone of zones.
This classic episode is among those that reveal Rod Serling's singular capacity to employ visionary dimension to his stories from either side of time's turbulent tunnel.