The Seven-Per-Cent Solution

Blurb

The Seven-Per-Cent Solution: Being a Reprint from the Reminiscences of John H. Watson, M.D. is a 1974 novel by American writer Nicholas Meyer. It is written as a pastiche of a Sherlock Holmes adventure, and was made into a film of the same name in 1976.
Published as a "lost manuscript" of the late Dr. John H. Watson, the book recounts Holmes' recovery from cocaine addiction and his subsequent prevention of a European war through the unravelling of a sinister kidnapping plot. It was followed by two other Holmes pastiches by Meyer, The West End Horror and The Canary Trainer, neither of which has been adapted to film.
The Seven-Per-Cent Solution was ranked ninth in the Publishers Weekly list of bestselling novels from 1974 and made the The New York Times Best Seller list for forty weeks between September 15, 1974 and June 22, 1975.