在一次反恐行动中，由于情报失误，英国特警部队误杀了一名怀抱孩子的中东移民，负责行动队的首长决定将这宗丑闻彻底抹去，遂找来了知道真相的队员们统一口径，录制假口供。刑侦队长史蒂夫（马丁·康普斯顿 Martin Compston 饰）对于首长的决定十分不满，于是辞去了职务，被调往隶属于英国反贪署的秘密行动组。 史蒂夫的任务是调查一位名为托尼（连尼·詹姆斯 Lennie James 饰）的侦缉总督察，他因为涉嫌贪污而被列入了监视的名单。史蒂夫和女警探凯特（薇琪·麦克卢尔 Vicky McClure 饰）一同打入了托尼所领导的小组内部，史蒂夫却意外的发现，凯特还有另外一重秘密的身份。

Mr. Finch (Michael Emerson), a mysterious billionaire, developed a computer program for the government that predicts terrorist threats to the US. It was designed as a means to prevent another 9/11-type disaster, but Finch discovered that it was also predicting many "irrelevant" (non-terrorist) crimes. The non-terrorist data is dumped to a separate database and deleted each night. Finch realized that a great many domestic crimes could also be prevented if that data could be used. Finch built a backdoor into the machine that allows him to retrieve a list of Social Security numbers of people who will be involved in those crimes in order of occurrence. Unable to investigate the data on his own, Finch hires John Reese (Jim Caviezel), a former Green Beret and CIA field officer who is presumed dead, to help stop the crimes from taking place. The world thinks that Finch, like Reese, is dead. Finch made the choice of only transmitting the Social Security Numbers of the persons of interest so that if the backdoor is discovered, the government would have no clue as to what the numbers mean or that Finch is still alive.

出生于巴基斯坦移民家庭的高中生纳兹（里兹·阿迈德 Riz Ahmed 饰），偷偷开走父亲的出租车去赴一场朋友爽约的派对。他中途迷路，焦急之际搭载了带着落寞绝望表情的女孩安吉拉（索菲亚·布莱克-德埃利亚 Sofia Black-D'Elia 饰）。霓虹闪烁的海边，两人互吐 心声。纳兹随对方回到家中，在迷幻的氛围中一切自然而然地发生。可当他醒来时，却发现安吉拉已被人残忍杀害。他惊慌失措，夺路而逃，结果半路因酒驾遭到逮捕，继而因涉嫌杀害安吉拉遭到指控。在押期间，善于为边缘人辩护盈利的小律师约翰·斯通（约翰·特托罗 John Turturro 饰）决定帮他洗脱罪名。临近退休的警长丹尼斯（比尔·坎普 Bill Camp 饰）和检察官海伦（珍妮·柏林 Jeannie Berlin 饰）则磨刀霍霍，发誓要坐实纳兹的罪名。 被人称为有着“小鹿斑比似的大眼睛”的纳兹，更要在炼狱般的牢房内接收黑暗和罪恶的洗礼……