Holmes 'most classic story was Watson and Holmes from the Cosmo series. Story summary: Watson was Holmes 'assistant. They investigated many cases together, the most famous of which was the "Red Letter Society" case. Holmes and Watson studied the case together and finally discovered the truth. In this story, the friendship between Holmes and Watson deepened. Story Details: - Holmes and Watson went to London together to investigate the case of the Red Letter Society. They found out that the organization used gambling to make money and their secret operations were discovered by the stalker. Holmes and Watson found out the identity of the pursuer through reasoning and finally brought the criminal to justice. - Holmes and Watson also investigated many other cases together, including the Möbius case and the Chessboard case. They solved these cases through reasoning and professional knowledge. - In this story, Holmes and Watson also spent a happy Christmas together. Holmes told Watson about his childhood experiences during Christmas, and Watson showed Holmes his reasoning ability. Read more: The Cosmo series was one of Sherlock Holmes 'masterpieces. The plot was compact and the reasoning process was wonderful. If you like Sherlock Holmes, this book is definitely worth reading.