影片是根据谢尔盖·卢科扬涅科的三部曲中的第二部《守日人》改编。 故事发生在上一集叶戈尔（德米特里·马丁诺夫 Dmitry Martynov 饰）归入黑暗阵营几年之后，安东(康斯坦丁·哈宾斯基 Konstantin Khabenskiy 饰）与其新女友兼徒弟斯维塔担当光明阵营力量的同时，叶戈尔也在逐渐成长为黑暗阵营中一名拥有强大力量的少年，并受到父亲安东暗中的保护。直到黑暗阵营中一名吸血鬼的离奇死亡，打破了光明与黑暗之间的微妙平衡，安东更被诬陷为凶手。审判庭裁定如果在期限之内无法证明安东不是凶手，光明和黑暗两大阵营之间的大战将一触即发。为此，安东开始寻找古代传说中那能改变命运的神器——命运粉笔，来挽回这摇摇欲坠的世界……
Like Fritz Lang, David Fincher or Bong Joon Ho before him, talented debut filmmaker Lado Kvataniya uses the concept of police detective vs serial killer for an excitingly stylised, macabre and haunting narrative, that ultimately revolves around the identity of an era in this case, the late 1980s Soviet Union. With Glasnost and the end of communist rule, the West also learned of the (unsurprising) fact that there were serial killers in Russia too – the most notorious case probably that of Andrei Chikatilo, nicknamed the Rostov Ripper, or the Russian Hannibal Lecter. Based on these and many other sources, Kvataniya and screenwriter Olga Gorodetskaya constructed an immersive psychological puzzle, jumping back and forth in time, to reveal ever new-possible motives for the actions of all the protagonists. It all starts in 1990, when Detective Issa Davydov is celebrating his promotion and receives a call, reporting a crime that looks precisely like the ones of the serial killer that he famously captured some years before ...