Do not google Samuel Jean Pozzi. If you want to enjoy Julian Barnes’s The Man in the Red Coat — and believe me, it’s teeming with delights — stay away from search engines and trust the author to tell the story in his own way.

But just to get you started: Pozzi (1846–1918), the man John Singer Sargent painted, gloriously, in sumptuous red, was a Frenchman, a prominent, pioneering doctor in Belle Epoque Paris, and a charming, ubiquitous, infallibly seductive socialite.