The Wedding Reception and the Two Gunshots

Sonoko must go to a wedding representing her family, and since she doesn't want to go alone she ropes Conan and Ran into going with her. The groom is the eldest son and heir of the incredibly rich Hatakeyama family, and he's marrying a young woman named Miho. The wedding takes place in a very nice villa, and things go well at first until the end of the reception.