故事发生在伦敦大都会公共图书馆中，在那里，蛰伏着一个历史悠久的古老组织，组织负责调查超自然的神秘事件，抵抗不明力量的入侵，保护古老文物不落入不法之徒手中。作为组织头目，图书管理员弗林（诺亚·怀尔 Noah Wyle 饰）一直尽忠职守，然而，随着时间的推移，他发现，仅靠一人单打独斗就能成事的时代已经过去了，弗林决定替组织吸收新鲜的血液。 精明强干的反恐专家埃文（丽贝卡·罗梅恩 Rebecca Romijn 饰）、智商超高的石油工人杰克（克里斯蒂安·凯恩 Christian Kane 饰）、拥有超能力的卡桑德拉（林蒂·布丝 Lindy Booth 饰）、超级电脑高手琼斯（约翰·金 John Kim 饰），这四名训练有素的新鲜人能否让弗林满意呢？
“In the early 1990s, at the height of the international war on drugs, the government agency in charge of Britain’s borders, Her Majesty’s Customs and Excise, realized that they were losing the battle against drug smuggling. Their solution was extraordinary,” reads the logline. “In a top-secret operation, a small team of British Customs employees were sent undercover. Their task – to infiltrate Britain’s most dangerous drug gangs.” “They were not trained spies. These were ordinary men and women, plucked from ordinary lives around the U.K, put through a basic training regime then told to build new identities in the criminal underworld. These identities were called Legends.
改编自维克托·拉瓦列2013年的小说《The Devil in Silver》。聚焦搬运工人Pepper（丹·史蒂文斯 Dan Stevens 饰），因为坏运气和坏脾气，他被送到了一所名为New Hyde的精神病院，里面满是被社会遗忘的人。Pepper想要获得自由，就必须面对与他作 对的病人、怀着阴森目的的医生，甚至恶魔本人。这里是地狱般的地方，任何事情都不是表面那样，Pepper必须直接面对一个以New Hyde里人们的苦痛来蓬勃壮大的存在，但这样可能会证明：最可怕的恶魔恰恰是他自己。
