The narrator in Dickens's short story "The Signal-Man" is intrigued by the signalman he meets because of the man's strange behavior. The narrator notices that "a fallen colour" seems to overcome the signalman's face for no apparent reason, and he continually gets up to peer in the direction of a red light as if in anticipation. The narrator is able to coax the signalman into expressing that he is "troubled." After making the narrator wait until a second visit—part of Dickens's means of maintaining suspense—the signalman explains to the narrator that he once heard a voice call out "Halloa! Below there!" and saw a figure waving furiously as if in warning. When the signalman approached the figure, it disappeared. Shortly thereafter, an accident occurred on the line, causing the signalman to believe that the figure was some sort of portent. What particularly unsettled the signalman was that these were also the first words the narrator said to him.
The signalman then explains that this has, in fact, happened to him twice. The second figure he saw did not wave, but held an arm over its face. Shortly after this vision, a woman "died instantaneously" in a train.
By this juncture, the narrator is afraid that these stories are true—his "mouth was very dry" and a "frozen finger" seems to trace his spine.
Then the signalman confesses that "the spectre came back, a week ago," and seems to wave at the danger light "now and again, by fits and starts." This has been the cause of the signalman's strange behavior.
The narrator tries to persuade the signalman that what he is seeing is only his imagination, but the signalman will not be dissuaded. He is distressed at being unable to alert anyone to a danger he is sure is coming, having no power to act and no knowledge of what or when the danger will be.
Towards the end of the story, however, when the narrator returns to the signal box on the night following this disclosure, he is taken by surprise—"oppressed" by a "nameless horror" at the sight of a man "passionately waving his right arm" under the danger light, exactly as the signalman described. This shock passes "in a moment" when the narrator recognizes that the light is not lit and that the man is really a man and not a ghost. The narrator, however, retains an "irresistible sense that something was wrong," and this is justified when he is told—to his complete surprise—"Signalman killed this morning, sir."
It is then explained to the narrator that what he saw the man demonstrating at the danger light was what he, in fact, had been doing in an attempt to get the signalman to move off the rails. This man causes the narrator a further chilling shock—"I started"—with the revelation of what he had been calling to the signalman: "For God's sake clear the way!"
These were the exact words the narrator had himself thought of as a description of what the signalman's waving arm conveyed. To hear these words from the unnamed man, then, is a further shock beyond that of the signalman's death. The narrator concludes by saying:
I may, in closing it, point out the coincidence that the warning of the Engine-Driver included, not only the words which the unfortunate Signalman had repeated to me as haunting him, but also the words which I myself—not he—had attached, and that only in my own mind, to the gesticulation he had imitated.
He does not explicate exactly what he believes has happened, but the implication is that the signalman had, in fact, been somehow seeing portents of his own death.