Conan, Mouri and Ran all go to an isolated mansion called the Sunflower building because every 12 hours it rotates. They are having a bbq outside while the owner is inside when they hear a shot fired. They rush inside to find the owner shot through the forehead. After investigating, Conan discovers the culprit was one of the owner's students studying to be an architect. The student killed the owner because the owner stole his work and was getting an award for it.