A comforting thought for those huddling by the hearth, with only wattle-and-daub walls separating them from the hare hildstapan, the “grey-frost warriors,” or “hoary battle-marchers” of ice and snow.

I have to admit I’ve been enthralled by the BBC’s wonderful A Ghost Story for Christmas series ever since I was old enough to stay up to watch, and to be troubled by, “The Signalman”, a relatively ...