The world's greatest blue sapphire, the "blue lapis fist", said to have sunk in a pirate ship in the late 19th century, on the coasts of Singapore. A local millionaire plots to retrieve it, and when it's exhibited at the Singaporean Marina Sands hotel, a murder takes place. A bloody Kaitou Kid announcement card is found in the crime scene.In the meantime, Ran and Sonoko have come to Singapore to see a karate tournament held there. Conan was supposed to stay at home. But Kid uses a magical trick to forcibly drag him to Singapore...