Nobue is found dead with a poisoned arrow in her back while holding a clean arrow in her hand. Ogito's crossbow is found near the scene leading the police to suspect him. Later, Ogito falls down a cliff due to being shocked by an electric fence. Conan, realizing how the events transpired, tranquilizes Kogoro and reveals how the three died. Katayose poisoned himself and hoped to frame his children in order to protect Nakakita from their greed. Nobue, seeking to increase her inheritance, set up the crossbow and held an arrow in her hand to frame Ogito for attempted murder, but was instead murdered by Ogito. Ogito meanwhile, figured out the location of the treasure which is placed inside a cross made of metal rods. As he attempted to remove the treasure, Suzuka re-activated the electric fence which unintentionally resulted in his death. As for the treasure, it reveals Katayose leaves his inheritance to Nakakita who is actually his blood-related granddaughter from his former love.
