"The Seven-Per-Cent Solution" is a novel by Nicholas Meyer that presents a fictional account of Sherlock Holmes and his struggle with cocaine addiction. Set in the late 19th century, the story follows Holmes as he seeks treatment for his addiction, which leads him to Sigmund Freud, who becomes a key character in the narrative. The plot revolves around Holmes's investigation into a criminal conspiracy while he undergoes therapy. The novel blends elements of mystery and psychological exploration, offering a unique perspective on the iconic detective and his relationship with Dr. John Watson, his loyal friend and confidant.