As Conan and the others are going to a seafood restaurant for lunch, Sonoko feels sleepy, and stays in the car while the others go to eat. As the group is chatting, Conan suddenly notices that the car Sonoko was in is moving, and heading straight for a cliff! Thankfully Sonoko is saved by Ran and Conan, but obviously someone is trying to kill Sonoko. After the accident the group go for a walk in the forest only to get separated from one another. Can Conan and the others find Sonoko in time?