In Ulan Baatar, a high-profile criminal prosecution collapses as police evidence is revealed to have been faked. The female judge, Radnaa, throws out the case and the defendant, Muunokhoi, a wealthy and influential businessman with suspected links to organised crime, walks free. Meanwhile, on the Mongolian steppes, the police discover the body of a woman who has been tortured before being killed. Nergui is assigned to conduct an internal enquiry into Muunokhoi's failed prosecution, while Doripalam has to deal with both a major murder investigation and suspected corruption in his own team. Tunjin, an alcoholic and overweight member of the Serious Crimes Unit, is suspended, accused of forging evidence in an attempt to secure Muunokhoi's prosecution. Cut adrift from the police, he realises that Muunokhoi's men are pursuing him, determined to exact revenge. He flees to the industrial ruins of the city, knowing it is only a matter of time before he is discovered. As Doripalam faces gunfire in the northern mountains, Nergui is attacked and Judge Radnaa is kidnapped. Meanwhile Tunjin decides to take matters into his own hands. And, as Nergui frantically tries to put together the pieces of this jigsaw, he begins to realise that Muunokhoi's influence is more malign and far-reaching than he could ever have suspected.