Serling's "Dust" is one of the more low-key episodes in the series, but one that sells its point -- about the power of love and forgiveness in the face of despair -- with well-drawn characters instead of one-dimensional caricatures. In a dying southwestern village anticipating a hanging, a sleazy peddler (Thomas Gomez) convinces the desperate father (Vladimir Sokoloff) of the condemned man that he has a magic dust that changes hate into love.
Although Serling could get preachy with his later episodes (the later, yet similar, "I Am the Night, Color Me Black" is a good example), the speeches in this story well directly out of the characters, particularly Sokoloff, whose anguish is palpable. Likewise, Gomez' actions are driven by greed and a general misanthropy, and John Larch's by an exhausted cynicism. The town's desperation is made manifest in the production design, and in the well-drawn characters.
Beware, however, of cuts of the show that edit out the last scene with Gomez and the children -- this scene is the true Twilight Zone twist, which ties the entire show together.