I chose to read Conan Doyle's book because the high school detective in Conan admired Sherlock Holmes. In order to fully understand Conan, I also found a story about Sherlock Holmes. After watching it, I felt the same way with Hitchcock, the famous suspense film director. The Signs of Four is indeed a classic in mystery novels. Maybe it's because Dr. Watson used some fascinating techniques when he wrote it, and I still don't fully understand it.

The Sign of Four tells the story of several prisoners taking away the priceless treasure left by the overthrown king. Several people signed a promise that the hidden treasure would belong to them, and then the four men refused to tell the location of the treasure and went to prison. Several people discussed the matter and told two warders to give them some treasure in exchange for their freedom. Unexpectedly, one warden killed another warden, ran away with the treasure and lived a rich life. Four prisoners also escaped. Finally, only one prisoner found the warden and sent him four rubbings. Since then, the warden can't afford to get sick. When he made his will, the warden's nephew saw someone outside the window. The next day, the warden died, and they asked Holmes to investigate the case. The clever Sherlock Holmes solved the whole case only from a clue of a signature fragment at the bottom of the folder. The plot of the story is tortuous, the ending is unexpected, and Holmes' insight is convincing.

After reading this story, I found that knowledge originally came from accumulation and cultivation in life. When you see an old watch, you can know that the owner is from a good family and often has financial difficulties. This watch is a clue handed down from the previous generation. Perhaps Baker Street is a mysterious place, hiding many classic stories waiting for future generations to dig.