_The Signalman_ of the title tells the narrator of a ghost that has been haunting him. Each spectral appearance precedes, and is a harbinger of, a tragic event on the railway on which the signalman works. The signalman's work is at a signalbox in a deep cutting near a tunnel entrance on a lonely stretch of the line, and he controls the movements of passing trains. When there is danger, his fellow signalmen alert him via telegraph and alarms. (Wikipedia)