In the present, Conan and his friends attend a chess tournament to support Inspector Shiratori. During the tournament, accompanied by "Amazing Grace," a murder occurs. Conan solves the case with the help of tournament participant Director Kuroda and Professor Agasa, who arrives later.

After the case, Kuroda begins to tell Conan about events from 17 years ago in America. At that time, he was not traveling privately but on a secret mission for a meeting with the wealthy Amanda Hughes. She was visited in her hotel room by Rum, an agent of Karasuma Renya. Rum had identified and neutralized Amanda's numerous bodyguards thanks to his photographic memory. He blackmailed Amanda with the life of her closest confidante, Rachel Asaka, whom she had raised like a daughter.

To protect Asaka, Amanda sent her under the pretense of retrieving a forgotten knight to the room of Shogi Meijin Haneda Koji. Haneda hid Asaka when Rum's men appeared. Rum saw through the deception, confronted Haneda, and forced him to drink poison. Dying, Haneda left behind an encoded message with a broken hand mirror.

Kuroda, alarmed by the loss of contact with Amanda, found her dead in her room. She had left a cryptic message in lipstick on a chess bishop and a clock. Subsequently, Kuroda also discovered Haneda's corpse in his room and found the broken mirror as a clue. While fleeing, Kuroda encountered Asaka, who had found Amanda dead. After a fight, during which Kuroda initially believed Asaka to be guilty, she escaped with a chess bishop that Haneda had given her as a "good luck charm" and a symbol for a future counterstrike ("The far-sighted bishop is a clever chess move"). Meanwhile, Rum tasked the sniper Chianti with eliminating Asaka. Kuroda was unable to apprehend Asaka at the time, and the murders remained unsolved. In the present, he recounts these pivotal events to Conan.