Remains of bodies are found in the sewer, which Carp tries to associate with the murder mystery he is investigating. Laura goes to the hospital and Nurmi starts tracking down the missing Leo boy. Henna is under pressure from both criminals and police.

The riddle of the symbol takes Karp and Nurmi to investigate the overdose death of a young girl a year ago. Henna is exposed and enters the spring from the ditch. Nurmi gets hold of a video of a dashboard camera shot in Germany that shows a surprise related to Karp's man overrun.