A Ghost Story for Christmas: The Signalman (BBC, 1976)
"The tunnel collision is the worst to be feared. Your nightmares would go hard to equal it. The wreckage becomes hideously compressed in the confined space. If fire breaks out, the tunnel and its ventilating shafts become furnace flues. You cannot see in the dark to get the wreckage and the bodies out. The screams of the injured and dying echo in a most... persistent way. It's the shape of the tunnel, you see, sir."









