The police department begin to find locations related to the number 7. They found three bombs at three different locations. However all 3 turn out to be fakes. Meanwhile the suspect disguise as a policeman, cause a Megrez Security vehicle to explode using the second bomb that flow down the sewage. The vehicle have a picture of Ursa Major printed on it, Conan and Ran realised it is the Big Dipper and the Center star is Megrez, the middle of 7.