The blurb on the back:

Little could Dr Watson believe that the pathetic figure huddled before him was the great detective, Sherlock Holmes. Alas, it was his old friend Holmes, but a Holmes in bondage - not to any archvillian - but to a 7% solution of cocaine and sterile water. Driven by the drug to wild ravings, Holmes had to be duped into rehabilitation - before it was too late.

Since his marriage, Dr Watson has somewhat lost touch with Sherlock Holmes. So he's a bit concerned when the detective arrives at his house late at night in a state of fear and paranoia, ranting about the evil mastermind that is Professor Moriarty. Particularly when Holmes then falls asleep and, on awaking, seems to have no knowledge of their previous conversation.

Working out that it's not Holmes but the cocaine speaking, Watson consults Stamford (the man who first brought them together); he suggests a controversial physician in Vienna who claims to know more about coke addition and its cure than anyone else. So, with the inevitable assistance of Mycroft, Watson tricks Holmes into travelling to Vienna to consult the then-unknown Sigmund Freud. The depths to which Holmes has sunk can be gauged by the fact that, simply from the presence of the Talmud and a Menorah, he deduces that Freud is Jewish - frankly, even Lestrade could have worked that out.

Admittedly, the story's both trite and thin, but there's the usual fun to be had with the re-interpretation of the mythology. Meyer takes the extreme step of having Watson admit that both 'The Final Problem' and 'The Adventure of the Empty House' are fictitious. Having thus disposed of the idea that Moriarty and Holmes fought to the death on the Reichenbach Falls, he can then advance the perfectly plausible theory that - far from being 'the Napoleon of Crime', as he appeared in Holmes' coke-fuelled paranoia - Moriarty was actually a harmless maths teacher, who at one stage attempted to drum the principles of calculus into the heads of the young Sherlock and Mycroft. Watson shares our excitement at this discovery:

'You didn't by chance write a treatise on the Binomial Theorem?' I interrupted.
He stared at me
'Certainly not. Who has anything new to say about the Binomial Theorem at this late date? At any rate, I am certainly not the man to know.' (p.31)

It should go without saying that Sherlock's obsession with his former tutor stems from a childhood trauma that only that good charlatan Dr Freud can uncover.

The Seven-Per-Cent Solution is purportedly written towards the end of Watson's life in 1939, though set in 1891, which gives Meyer a flimsy pretext for flaunting his research into late-Victorian British society - a long explanation about why Holmes and Watson used cabs instead of the tube, for example, or this on cocaine:

...recently, I have even heard it suggested that my willingness to supply Holmes with his drug was the only reason he tolerated my companionship. Without pausing to comment on the patent absurdity of the suggestion, I will only note that Holmes had no such need. No statutes in the previous century prevented a man from purchasing cocaine or opium in whatever quantity he pleased. It was by no means illegal...

It's all a tad clumsy, and isn't helped by a letter in the Introduction supposedly written by an Englishman in 1970, which refers to 'Aylesworth Home, an old folks' affair recently taken over by National Health.' National Health? The NHS, possibly, or perhaps the National Health, but surely not National Health?

Nonetheless, this became a huge success, probably the biggest of all the Holmes rip-offs, and even got made into a film in 1976. (Which was rubbish.) Meyer went on to give us The West End Horror.

An extra pipe has been awarded in recognition of the service this book provided in inspiring the publication of many, better works.