There’s an affinity between trains and Christmas, but what precisely is the connection? Ghostliness comes into it – the mystique of a train in the wintry night. I think of the misty, hypnotic adaptation of Dickens’s story The Signalman, in 1976, part of the BBC’s A Ghost Story for Christmas strand; or the ghost story in the Christmas number of the Railway magazine (that publication’s only excursion into whimsicality is always worth reading).