93-year-old Sherlock Holmes, with white hair and stumbling, needs the care of the housekeeper in his daily life, but he still has strong observation and reasoning ability, but his memory is not as good as before. In order to alleviate the memory loss, he tried to eat royal jelly and rock pepper and began to recall his last case. This stems from the fact that when he was sorting out his brother's relics, he saw a case described in Watson's novel and felt familiar with it, but the ending was not quite right. He only remembers that this was his last case, which is why he stopped being a detective and moved to the countryside to raise bees. He decided to pursue the facts and restore the truth.

Mrs Munro, the housekeeper, lives alone with her son Roger, who is an admirer of Sherlock Holmes, the most loyal reader of the manuscript and a conscientious beekeeper. An old man and a young man gradually became friends. They hid their own shortcomings in front of Mrs Munro, whispered away from her, went swimming at the seaside together, and chased down the real bee killer. ...

Sherlock Holmes' manuscript is not well written. He tries hard to recall and reason, but his mind is always blank and has no clue. Once, Roger helped Holmes find a magnifying glass and accidentally found a glove, which was used by the heroine. By combining this glove with fragmented memory and reasoning, Holmes finally remembered all the details of the case.

That was decades ago. Kelmer turned to Sherlock Holmes and told his wife Ann that she was pregnant and had a miscarriage. In order to divert her depressed mood, Ann went to learn the glass piano. However, during this time, Ann has changed abnormally. She often talks to herself, just like chatting with a child. Kelmer suspected that the music teacher had bewitched Ann. He restricted Ann's freedom of money and asked Holmes to investigate the truth.

Holmes followed Ann's whereabouts and movements and saw her copy her husband's signature to withdraw money from the bank. Then she went to the notary office to confirm her will, went to the drugstore to buy poison water and gave a lot of money to people near the railway station. Then she sat there in a daze. Holmes approached Ann and talked with her. Ann knew that her husband had asked Holmes to investigate herself, but she thought only Holmes could understand her feelings.

Ann experienced two pregnancies and miscarriages. Her husband deprived her of the fun of learning music and asked someone to investigate herself, which made her feel deeply lonely. Holmes himself is lonely and understands Ann's loneliness. Through tracing all the way, he learned that Ann wanted to end her life with poison and hired someone to make tombstones for herself and her unborn child. Two lonely people have the same fate, but Holmes persuaded Ann to go back to her husband because of his own fear and weakness. Ann obviously agreed, but a few hours later, she chose the speeding train to commit suicide.

This incident touched Holmes very much. He regretted persuading Ann to go back to her family and sending her to the point of no return. He also understood that solving a case by logic is not everything. From then on, he chose self-exile, self-punishment and came to the countryside to spend the rest of his life.

At this point, Holmes finally got rid of an annoyance. But an accident happened. In order to protect the bees, Roger was stung by wasps all over his body. During the doctor's treatment of Roger, Holmes and Mrs. Munro opened their hearts and communicated frankly, and said that they could move into a nursing home, only hoping that Mrs. Munro and Roger would not leave. Roger was finally out of danger. Mrs Munro was moved by Holmes' words and gave up her job in a hotel in the town to continue to take care of Holmes and his precious bees with Roger. ...