Kudou Shinichi is the current teenage in the spotlight, being a brilliant young detective he is. His popularity makes him receive a strange letter from an unknown sender declaring a challenge. It is said in the letter that something bad will happen at his school's trip and Shinichi has to solve the case. The 'bad thing' mentioned in the letter does happen. His classmate, Suzuki Sonoko, goes missing mysteriously. After a few days, another challenging letter comes and this time it is Shinichi's childhood friend, Mouri Ran, who vanishes. Being given 24 hours as a time limit, he has to save both of the girls before a time bomb at the place where the girls are kept explodes.