A group of employees of the external surveillance service of the St. Petersburg FSB conducts operational activities to develop members of an organized criminal group suspected of smuggling . It suddenly turns out that, in addition to participating in illegal transactions with non-ferrous metals, one of the criminals is a link in a long chain of intermediaries through which terrorists buy the most modern weapons in Russia and abroad... Welcome to the mysterious world of "invisibles" from special units of the FSB! Without them, not a single preparation for a serious operation . They are highly qualified professionals .. Excellent analysts, actors and ... ordinary people who have their own quite earthly problems .