The Seven-Per-Cent Solution (1986)

First published in 1974, this is a 1986 paperback edition of Nicholas Meyer's bestselling Holmes novel, The Seven-Per-Cent Solution. Over two million copies in print then, and it's still in print today.

SHERLOCK HOLMES AND SIGMUND FREUD
TOGETHER AGAIN FOR THE FIRST TIME!

First discovered and then painstakingly edited and annotated by Nicholas Meyer, The Seven-Per-Cent Solution related the astounding and previously unknown collaboration of Sigmund Freud with Sherlock Holmes, as recorded by Holmes's friend and chronicler, Dr. John H. Watson. In addition to its breathtaking account of their collaboration on a case of diabolic conspiracy in which the lives of millions hang in the balance, it reveals such matters as the real identity of the heinous professor Moriarty, the dark secret shared by Sherlock and his brother Mycroft Holmes, and the detective's true whereabouts during the Great Hiatus, when the world believed him to be dead.

Title: The Seven-Per-Cent Solution
Author: Nicholas Meyer
Year: 1986 (first published 1974)
Publisher: Ballantine
Purchase: Amazon.

Read: The case of the non-canonical seduction.