It is difficult to know where to start a description of this book. Julian Barnes suggests several possible ways he could have started to write it. He chooses to begin with a portrait of Doctor Pozzi, the eponymous Man in the Red Coat – but not always. Pozzi was painted wearing the red coat by John Singer Sargent. That seems a secure basis on which to build a biography , or maybe a diorama of the Belle Epoque?  Whichever this book is going to be, the painting leads naturally to the 1885 visit to London made by Pozzi and two friends, bearing a letter of introduction written by Sargent and addressed to Henry James.

But the description of one of the party, Count Robert de Montesquiou-Fezensac, that begins on page nine, morphs into a description of a fictional character based on the Count, in a book (A rebours) written by one of his contemporaries. The actual and fictional characters are compared and contrasted, there’s a digression into opinions about Englishwomen, as voiced by Frenchmen of the time, then just as we it seems we are returning to the actual Count, Julian Barnes points out a link between A rebours and the trial of Oscar Wilde for gross indecency. And that trial is compared with another. Ten pages later we return to Montesquiou and Pozzi.

I started making a list of the writers, artists, academics, politicians and one actress that are name checked in the next pages where Julian Barnes makes links between events, points out coincidences and quotes from the writing of Pozzi’s contemporaries. In a dozen pages I met, fleetingly, more than two dozen historical figures, most of whose names I recognised.

It was like being at a glamorous party, full of celebrities, and not being sure why I was there. A couple would whirl past. Before I’d mouthed wasn’t that …? they’d moved on and wow! there’s Sarah Bernhardt. It wasn’t thirties Hollywood, it was Paris during La Belle Epoque – and Doctor Pozzi, it seems, knew everyone.

Julian Barnes plunges his readers into the period, and we are dragged along like children taken to a funfair – look at this, don’t miss that. It’s exciting and enthralling – and confusing.

I think it was Forster who said Only connect, and Julian Barnes does. Wonderful, sometimes logical, sometimes coincidental links – like the one he makes between a French colonial expedition and de Gaulle and Brexit; or between re-establishment of a sense of honour in Frenchmen after the 1870 Prussian defeat to the persistence of formal duelling, and links between arguments about whether gun control should outweigh the right to bear arms in that time and now.

It is like watching a meteorologist explaining a weather system. The storm on the coast links to low pressure here, and the gulf stream there, and cold air from the Pole came in this way, and pressure built over here – and suddenly she’s talking about a butterfly off the coast of Peru.

The illustrations help – there are full-page colour reproductions of famous paintings of celebrities, monochrome (of course) studio photographs and, most wonderful, portrait cards that were given away with Felix Potin chocolate bars. These, for me, were most evocative of the time. With serious (long exposure) expressions, no background, the faces stare from their time into ours.

Another device that grounds the surging exploration is the tally Julian Barnes keeps of death, or injury, caused by gunshots. I think I counted fourteen episodes, though the bullet count was higher. The incidents are recounted partly to show how violent death (by gunshot or duelling) was as likely in Pozzi’s time in Paris as it had been in Shakespeare’s age in London. They also serve to show how medical techniques were developing, sometimes – but not always – saving a life that seemed condemned. Pozzi’s expertise and innovations were applied beyond his initial field of gynaecology.

Academics and politicians, as well as the chattering classes of Pozzi’s age were concerned with many of the issues that concern our time, for example the debate about Creationism versus Evolution and Geology, and racism, particularly anti-Semitism (the Dreyfus case). Dr Pozzi was an advocate for Listerism, asepsis within the body, and antiseptic outside it. He fought the same battle to enforce handwashing to prevent spread of infection that Semmelweiss lost, that was being refought in UK hospitals to prevent the spread of superbugs in hospitals before Covid and that seems vital to our survival now.

Julian Barnes (like this reader) was delighted to find Doctor Pozzi’s opinions chimed with his own – except, it seems, in the case of marital fidelity and doctor-patient relationships. Although Barnes re-iterates that there is insufficient evidence to substantiate all the affairs that are credited (is that the right word?) to the doctor.

Doctor Samuel Pozzi succeeds in becoming not just a guide, but also a hero of the Belle Epoque. He moves among the privileged, the dilettantes, the self-obsessed, appreciating what he sees and making lasting friendships while working hard in his chosen profession. As a gynaecologist he seeks to reduce both psychological and physical pain and scarring, and searches the world to find improved techniques. He declares that Chauvinism is one of the forms of ignorance. As far as we can tell he seems to live by this belief, and be determined to overcome ignorance wherever possible.

I have read this book twice, I am still confused and dazzled. There are no chapters, no Contents at the front, no Index at the back; no way besides post-its, annotations, notes or googling to check if we’ve met a character before, whether they were pro- or anti-Dreyfus, and what happened when. I had reached the point of wishing the book were different, then I read Philip Pullman’s Introduction to The Anatomy of Melancholy and realised that the diversions, divagations and meanderings could be embraced and enjoyed. The second time I read it I did just that.

One more point – I’ll never again forget the difference between a participle acting as an adverb qualifying an adjective and it acting as a substantive gerund. Thank you, Mr Barnes.