Kogoro, Ran, and Conan are on a hiking trip. When they reach the observation deck, they witness a man jump off the edge to his death. The body was found at the bottom of the hill and is identified to be Takaya Hirai. Conan investigates the scene and realizes that it was a murder made to look like a suicide. Conan tranquilizes Kogoro and reveals the murderer to be Eeichirou Kondou, Hirais co-worker. Conan explains that Kondou was the one who they saw jump off the observation deck and reveals that when Kondou jumped, he landed on a tree below the cliff where he then proceeded to push the unconscious Hirai off the tree. As evidence Conan reveals that the tree had a mejiro's nest and that a piece of the nest was found on Hirai. To incriminate Kondou, Conan explains that Kondou's footprint from his mountaineering boots was found on the tree. Kondou confesses and reveals that Hirai was blackmailing him after he accidentally caused the death of a co-worker.