Petra's memories have returned. The realisation that she was once a little girl called Mireille who was murdered by a serial killer has tipped her over the edge. After trying to kill Jenny and blowing herself up, she is now lying in a coma she is unlikely to wake up from. The second entity in her head now has the upper hand and he is slowly erasing Petra's existence while she lies helpless.

Jenny, Jackie and Sophie find Petra where her guardians have taken her. The Schumachers prepare the three friends for the worst, but the Musketeers do not give up on Petra that easily. They must confront the evil entity of Petter Ulfson and expel him from Petra's mind. But if they are successful, who will wake up? Petra Connell, who had finally admitted her feelings for Jenny, or Mireille Bouchard, Petter Ulfson's final victim?

Chief Inspector Fransson still has no clue as to where his serial killer has disappeared to, or the body of Mireille Bouchard but he knows Petra is the key.