繁华的东京夜空下，专为周刊撰写文章的记者町田广二（天知茂 饰）正在调查一个秘密卖淫组织，在街头算命女郎摩耶（三原叶子 饰）的指引下，他随神秘男子（鸣门洋二 饰）来到站前旅馆。广二误饮掺有安眠药的饮料，昏昏睡去，待醒来时发现自己的身旁竟躺着一具少女的裸尸！

Freelance reporter “Scoop” Machida is hot on the trail of a prostitution ring called the Black Line, when he is framed for the murder of a young woman. Forced to clear his own name, the handsome journalist sinks deeper into the Black Line’s rotten swamp of drugs, prostitution, and murder and finds unexpected help in Maya, a steamy female gambler familiar with the neon-lit streets, shadowy alleyways, and seedy nightclubs he must navigate. The closest film in the Line series to classic American film noir, Ishii’s Black Line is a pulpy assortment of crime film conventions including the starkly expressionistic black and white cinematography by Jûgyô Yoshida, a jazzy music score by Michiaki Watanabe, and a sleazy screenplay by Ishii and Ichirô Miyagawa.