This book’s subtitle, ‘The Mysteries of Loch Ness’, lets slip the fact that the possible existence of a monster in those deep, cold Scottish waters is merely one of the enigmas it addresses – and not necessarily the most significant, either. The first two hundred pages of this lively and entertaining account are essentially a useful chronology of sightings of the monster, after which their plausibility can be examined in detail. Meanwhile, the drawback for the sceptical reader is that the lack of hard scientific evidence for the creature’s existence, the likelihood of hoax and the perennial delusion of credulous spotters make it difficult patiently to suspend disbelief.

We can dismiss the first recorded sighting by St Columba in AD 565 since there is no disinterested eyewitness account, still less any decent smartphone picture. Apparently the saint prevented the monster from devouring a swimmer by making the sign