Rudolf Heinz's life is far from perfect. His son avoids him, he's a terrible guitar player, and he lives in constant pain. But there is one thing Rudolf Heinz is really good at - he's the best profiler in Poland when it comes to serial killers. When the police find the dead bodies of two young men, their heads covered in plastic bags marked with the numbers 21 and 37, Heinz faces his most challenging case. Taking on a killer who likes to play games, the investigation is complicated when he discovers the victims are priests, and the local police close ranks against him. As he analyzes each lead, Heinz's search for the killer pushes him deep into his own past, unaware that he will soon have to save his own life. And he's running out of time -