The Detective Boys, Dr. Agasa, Conan, and Ai go on a camping trip together. While Dr. Agasa and Ai set up the camp, Conan and the Detective Boys start exploring. Genta finds a cavern. Thinking it might lead to a great adventure, he convinces the others to check it out with him. Conan reluctantly follows them in case they get into trouble. While exploring, they find three men disposing of a corpse. After the Detective Boys and Conan are spotted, one of the three men shoots at them as they run for cover. After Conan and the trio find a place to hide, they discover that Conan has been shot! With the three men on pursue of them, can they get out alive?