昭和初年，大侦探胜吕武尊（野村万斋 饰）乘东洋特快返回东京，谁知途中遭遇匪夷所思的事件。粗鲁蛮横的实业家藤堂（佐藤浩市 饰）在梦中惨遭杀害，而凶手可能就是该车厢中的一人。凭借现场的蛛丝马迹，胜吕对列车员三木（西田敏行 饰）、藤堂的秘书慕内（二宫和也 饰）、管家益田（小林隆 饰）、贵妇人羽鸟（富司纯子 饰）、侯爵夫人（草笛光子 饰）及其侍从昼出川（青木沙耶香 饰）、外交官安藤（玉木宏 饰）及其夫人（杏 饰）、陆军大佐能登（泽村一树 饰）、私家侦探羽佐间（池松壮亮 饰）、汽车销售员保土田（藤本隆宏 饰）、家庭教师马场（松岛菜菜子 饰）、教会人员吴田（八木亚希子 饰）等十数人展开问询。每个人都有确凿的不在场证明，众人的证词却又有离奇反常之处。在此期间，另一起沉疴数年的案件浮出水面，引出藤堂遇害背后的真相……
本片根据阿加莎·克里斯蒂的经典原作改编。

Before he was a protector, Kenshin was a fearsome assassin known as Battosai. But when he meets gentle Tomoe Yukishiro, a beautiful young woman who carries a huge burden in her heart, his life will change forever.

Hiroto Miyama is a poor lawyer who takes on criminal cases, but unable to make money. He pursues the truth for the 0.1% out of Japan's 99.9% conviction rate. One day, Hiroto is scouted by Haruhiko Madarame. Haruhiko Madarame is the head of Madarame Law Firm which is one of the biggest law firms among the 4 big law firms. Hiroto Miyama begins to work with Atsuhiro Sada. Atsuhiro Sada is a lawyer specializing in civil cases and makes lots of money for the law firm. He doesn't have any interest in criminal cases which can not make money.