The Sign of the Four, by Arthur Conan-Doyle

"This Sherlock Homes story was published in 1890 so contains actions and attitudes reflective of the Victorian era in which it was written..."

So begins the very good BBC Sounds audiobook of The Sign of the Four, read by Kenny Blyth and released in August last year. This is Holmes' second published adventure and a huge improvement on A Study in Scarlet (1888), where Part I is the detective story in which Holmes first meets Watson, and Part II is a wholly less engaging Western told to Holmes by the culprit he ensnares. The Sign of Four still ends with the culprit regurgitating his back story in one long info-dump, but it's done in a single chapter.

It's something like 20 years since I last read the canon of Holmes stories written by Doyle - the four novels and 56 short stories published between 1888 and 1926. Then, Jeremy Brett was indelibly "my" Sherlock Holmes, but there's since been Cumberbatch and Downey Jr vying for that title (and I've caught up with Rathbone, Wilmer and Cushing, too). I'd thought the 21st century Sherlocks made the original stories more pacey and action-packed so it was a gratifying surprise to return to The Sign of the Four, which I remembered as one of the better ones, and find so much adventurousness there.

The book is full of striking, strange incongruities. The villains are hard to forget: a one-legged man and his diminutive companion - who I shall not say more about rather than spoil it. But there's also the incongruity of Holmes scrambling barefoot across the roof of a grand house (Pondicherry Lodge in Upper Norwood, just up the hill from where I type this), or that Holmes gets access to the house in the first place because he happens to know the servant on duty at the door, having boxed with him for three rounds at a benefit fight four years previously. Even before that, there's the, "Hindu servant, clad in a yellow turban, white loose-fitting clothes, and a yellow sash," who opens the door of the only occupied house in a new, dull terrace just off Coldharbour Lane - even Watson notes that, "There was something incongruous in this Oriental figure framed in the commonplace doorway of a third-rate suburban dwelling-house." Later, there's the gathering of street urchins in the respectable rooms at Baker Street, and the oddness of the Sholto brothers whose case this partly is. It's all arrestingly peculiar.

I am also struck by how much of this story takes place south of the Thames, not least because the bit of London I've lived in for 20 years is so often overlooked by them northerners. Here, Thaddeus Sholto lives off Coldharbour Lane, his brother in Upper Norwood, Mary in Lower Camberwell, and Toby the dog in Lambeth, while Jonathan Small is brought to ground at Plumstead Marshes. Doyle didn't move to his house on Tennison Road in South Norwood until 1891, so I wonder why the south so appealed. The Victorian buildings of South London - including the one that I live in - seem old, but in Doyle's time this vast metropolitan sprawl was all new. Watson makes his feelings clear about these, "interminable lines of new staring brick buildings,—the monster tentacles which the giant city was throwing out into the country." Doyle fills these identikit buildings with distinct individuals.

The joy is that ordinary life is presented as being full of wonders, if only we trouble to look. Plus. there's the promise that these strange, seemingly random incongruities will be threaded together by Holmes. Famously, he demonstrates his deductive skills early on when Watson passes him an ordinary pocket watch, a scene all the best later Holmes stories whether by Doyle or his successors have attempted to emulate. Just from the engraving on the back of the watch and a few dents and scratches, Holmes deduces the life and tragic death of Watson's elder brother. The thrill is not in his insight, but that he then explains exactly how the trick is done.

"The implication is that we could replicate the experiment ourselves and learn to be like Holmes. As he challenges Watson in The Sign of the Four (and some later stories, too): 'You know my methods. Apply them.'" - Me, "My Immortal Holmes" in The Lancet Psychiatry

It's fun to see Inspector Athelney Jones attempt to play the game and come to the wrong conclusions. But Holmes can be mistaken, such as when he, Watson and Toby (a dog) follow a trail to the wrong place. There's his frustration, too, when the boat he is looking for completely disappears despite his ingenious efforts to find it. For all his brilliance, the investigation is not easy - and the more difficult for him it is, the more satisfying it is to read. But at the end, the incongruities are connected in a way that feels satisfying, logical, obvious - just as with the demonstration with the watch. Doyle doesn't cheat us.

Holmes here is more than an egg-head: he's a man of action. He can box, he can climb a roof, he can disguise himself so perfectly as a painfully asthmatic old man that his friend, housemate and doctor (Watson is all three) is entirely hoodwinked. The whole adventure is pacey and exciting, and culminates in a death-defying chase down the Thames. Holmes is dynamic, relishing the danger. He's exciting yet unemotional.

Watson is the romantic lead, drawn to Holmes' beautiful client Mary Morstan but prevented from acting on his feelings because she might be out of his league given the fortune she seems about to inherit. Time and again in his account, Watson tells us what Mary thinks now - as in, when he's narrating, looking back on these past events. That means we know she's never in any danger in the story, but that's not the point. The jumps forward help to build up the moral dilemma sub-plot of Watson falling for an heiress but not wishing to seem out for her money. Mary is very nice and moral, too, but there's not very much else about her. (Doyle wrote a more memorable woman - the woman - in his next Holmes story, "A Scandal in Bohemia".)

A lot of modern Holmes has attempted to make more of the women in his and Watson's life. Like Buchan, these boys' own adventures are too happy excluding girls. The treatment of India is interesting: yes, Doyle/Watson is condescending and there's a eugenicist link between Tonga's appearance and his personality. But it's not as simple as - in the works of other authors of the time - that foreign equates with bad. Watson's own military experience in Afghanistan is a source of pride and of melancholy, the life of ordinary Englishmen entwined with the orient and wider world. The Victorian attitude is imperial but nor parochial, and there's little sense of the white man being superior given their behaviour here. Given the evidence here, Watson is morally exceptional just as Holmes has an exceptional brain.