Mycroft was watching the movie intently. At the climax of the plot, the picture suddenly became unstable and the movie was interrupted.A strange voice echoed in the silence, repeating the strange prophecy that the east wind has arrived.Immediately afterwards, an exaggeratedly dressed clown rushed toward Mycroft brandishing a sword.Mycroft hurriedly took out his pistol, only to find that the bullet was missing.He tried to escape toward the door, only to find it locked.At this critical moment, Sherlock appears like a phantom, revealing a surprising fact: he has a sister named Eurolos.

Afterwards, Mycroft hurried to Sherlock's residence and told him and Watson about Eurolos' past.Eurolos, who has shown extraordinary intelligence since childhood, is known as a genius rarely seen in a century.Her brain is extremely developed and she can foresee fragments of the future. However, her ability also comes with devastating consequences.In one out-of-control prophecy, she predicted a catastrophic fire that actually caused the house to burn down.In order to protect his sister, Mycroft sent her to Sherlingford for secret detention and lied to her parents that she was dead.After hearing this, Sherlock still had no impression of this sister.

Suddenly, a drone flies over carrying a missile. As long as it moves within three seconds, the missile will detonate.Sherlock and Watson are forced to escape by jumping out of the window, while Mycroft escapes with Mrs. Hudson.During their escape, Sherlock and Watson cleverly disguised themselves as pirates, hijacked a ship, and successfully arrived at Sherrinford's island.After the warden learned of the situation, he immediately reported it to Mycroft, but Mycroft had already taken the lead and came to Sherrinford in person.After many tests, Sherlock finally met his sister Eurolos. However, Eurolos suddenly took action and knocked Sherlock unconscious.Watson and Mycroft witnessed the video of Eurolos manipulating people's hearts. Watson suddenly realized that the warden and the entire prison had been controlled by Eurolos.

Neither Watson nor Mycroft could take action, and the warden had no choice but to commit suicide, but Oros still killed the warden's wife.Then Eurolos asked Sherlock to deduce who was the real murderer of the shooting. Even if Sherlock's guess was correct, Eurolos did not let go of the remaining two innocent people.Eurolos also lied that he had planted a bomb in Jasmine's room, and that the bomb could only be deactivated if Jasmine said “I love you”, which caused great harm to Jasmine.Sherlock cheered up with Watson's encouragement.

Eurolos asked Sherlock to choose one of Watson and Mycroft to keep, and the other must be killed.In desperation, Sherlock wanted to end his life, but Eurolos stopped him.Watson is trapped in the well, and Sherlock realizes that it is not a wall that traps him, and when he pushes it open, he discovers that it is his own manor.Euros releases water to drown Watson, and the plane is about to crash.Only then did Sherlock remember that when he was a child, the person Eurolos hid was not a dog, but his good friend.Sherlock ran to the cemetery to look for clues and try to figure out the answer.It turns out that Eurolos was afraid of being alone and having no one to play with her, so she did such a thing.Sherlock comforts Euros and asks her to tell him how to save Watson.The little girl on the plane was Eurolos herself. Finally Eurolos was sent back to Sherlingford, and Sherlock often stayed with her from then on.