Haneda, the president of a company dealing in gold, is shot to death on the Raicho 9 limited express from Osaka to Kanazawa. Detective Kamei begins an investigation in cooperation with the Fukui Prefectural Police. In the Green Car, Detective Nishimoto had noticed a beautiful woman talking to the victim just before he was killed. Looking into her background, she turns out to be Yumiko Miura, living in Setagaya in Tokyo. An eyewitness who claims that she is the murderer also appears, and she is taken into custody. Before long, the victim's unexpected relationships will be revealed one after another...