The evil duo called The Pied Piper, had been on murder rampage throughout the series, sometimes leaving clues along the way. Their victims were brutally or savagely murdered, but there were also victims who were tortured and released. I didn't realize it at first, but the victims were somehow linked to the disappearance of a child some 20 years earlier. The mother had plotted revenge and her deeply disturbed boyfriend helped her carry it out.
In the finale, eleven people are randomly abducted and loaded into the back of a meat truck, along with Elise. The people are slowly being gassed to death in the truck, and Elise appears with a bomb strapped around her neck. Karl is told to choose. He can denotate the bomb and save the people, or save Elise.
Karl tried to negotiate, as he had found Saban, the missing boy, had been adopted and raised by a French couple. But PP would not tell the mother, and insisted that he had to choose Elise or the innocent people. When Karl hesitated to save the people, Elise (for the greater good), set off the bomb herself.
But it didn't end there. As police finally arrive on the scene, the couple takes off with Karl in persuit. He manages to ram the car and flip it. Of course, they survive. When Karl tells the woman about her son, she shoots the guy and turns the gun on herself, but Karl is able to stop her and she goes to jail. Karl brings her pictures of her son and tells her about his life, and that he is soon to be married. He asks her if she really wants her son to know all that she's done. It ends with her looking at the pictures. Of course, everyone else is grieving the loss of Elise.
Karl ties up the loose ends of a separate case that Elise had been working on that involved another child abduction. He found that a crooked cop had covered it up for money. It looked like Karl and his wife might get back together as it ended.
Sorry it's a little long, but no other way to explain it. I was really surprised to read all the great reviews and how popular the series was.
