"They eat the dark, who only stand and breathe"
This sounds like a reworking of the familiar final line from John Milton’s sonnet, “On His Blindness,” in which the poet wonders what use he might be to God without his sight: “They also serve who only stand and wait.” Bradbury, or rather Charles Halloway, turns the line from Milton on its head in thinking about idle people who may become more evil, or capable of it, while waiting for something to happen.