S1·E859 The Dark Mountain Route

While hiking, Conan and his friends meet campers Eiko, Ashizuka, Hayashida, and Takemi at a mountain cottage. The four of them have gathered to commemorate the death of their friend Motoki who accidentally fell to their death three years ago. Takemi, who camped by herself in a tent at the bottom of a cliff, is found murdered the next morning!