I think it’s no accident that in Wilkie Collins’ The Moonstone, there’s more than a suggestion of lunacy. Characters go mad with love or opium, or cultivate obsessions ranging from roses to evangelical tracts and Robinson Crusoe. And not all of them can offer the stone’s curse as an excuse.

Many readers have commented on the number of ‘firsts’ that the Moonstone represents for a mystery novel. I’ll offer a couple more that I didn’t see mentioned: first story in which a great detective initially fails to solve the case, then gets another shot and makes it count; and first story to use a device that’s brilliant in context, but can never be used again because it’s so unlikely and would immediately make any reader think, ‘The author is just copying The Moonstone.’

The journey, with its multiple narrators, is varied and satisfying. The nineteenth-century pacing means that it takes longer than you might have expected, and you wind up lingering in a few country lanes or village pubs while you wait for fresh horses, but that’s far from a bad thing. And then, of course, there’s the happy ending. Characters you like are rewarded (or possibly go to their graves still concealing terrible secrets that have ruined their lives, but hey, it’s Victorian times, so you have to expect a bit of that). Best of all, the Moonstone is returned to where it should have been centuries ago: the temple of the moon god, whose devotees include, whether they know it or not, most of the characters in this book.