A man is shot while jogging in the dunes. A woman in her car. Apart from the murder weapon, both cases have one thing in common: the perpetrator numbers the dead in messages that he sends to Tjark by text message. The investigating team is faced with a puzzle: Why is the perpetrator sending messages to Tjark? Why did he number the victims? Is it perhaps something personal? This last question no longer arises when Tjark receives the video of the kidnapped Barbara. It is addressed directly to him by the perpetrator with the words "For Tjark". A race against time begins for the investigators. Because if they don't solve the mystery and find the murderer, they won't be able to save Barbara. Although Tjark is taken off duty because of his private relationship with Barbara, he investigates with all his might on his own initiative. He soon sets his sights on Klaasen, a serious criminal - an old acquaintance of Tjark's, but also of Barbara's.
