Frozen Tracks

It's autumn in Gothenburg and an anxious mother calls the police: her little boy was lured into a car by a man offering sweets. The child is returned unharmed but then the same thing happens with a little girl, and then another. Each child attends a different nursery, and each parent contacts a different police station, so, at first, no connection is established and the reports are filed and then forgotten.
Meanwhile DCI Winter is investigating a series of random attacks on strangely uncooperative university students, but when a a four-year-old boy is abducted and found injured, the forgotten files resurface and a link between the stories becomes apparent. As Gothenburg prepares for Christmas, Winter is in a race against time to prevent a horrific catastrophe.