Suzanne Perry is having a vivid nightmare. Someone is in her bedroom, touching her, and she can't move a muscle. She wakes, relieved to put the nightmare behind her, but when she opens the curtains, she sees a Polaroid stuck to the window. A photo of her sleeping self, taken during the night. And underneath the words: "I'm watching over you". Her nightmare isn't over. In fact, it's just beginning.

Into the house. Down the stairs. Through the dripping dark of the cellar. Someone is there. Someone that shouldn't be there. As a building awaits demolition, a horrifying discovery is made inside the basement: a cage made of human bones - with a terrified, feral child lurking within. Unbeknownst to DI Phil Brennan and psychologist Marina Esposito, they have disturbed a killer who has been operating undetected for 30 years. A killer who wants that boy back.

But the cage of bones is also a box of secrets - secrets linking Brennan to the madman in their midst.

‘I have something you've lost,' the voice said. 'Your daughter.’ 'He Will Threaten her' The honeymoon is over for newlywed criminologist Marina Esposito. Her house is in flames. Her cop husband is in a coma. Her baby daughter is missing. And then her phone rings . . .'He will control her' The voice on the other end wants to play a game. If Marina completes a series of bizarre tasks within three days, she wins her daughter's life.

From the outside, the house was unremarkable. Just one of many on an ordinary, suburban estate. But inside was a different matter. With pink ribbons and pink walls, stuffed toy animals everywhere and a dining table laid out for a tea party, it was a doll's house. The doll was sitting at the table. Life size, with blonde, pigtailed hair and rosy red cheeks, dressed in her best pink party dress. Her finger and thumb curled round the handle of a fine china teacup.An adult woman. Covered in blood. Eviscerated. Dead.

Darren Richards opened his eyes to find himself duct-taped to a chair with a crossbow pointing at him. Behind the crossbow is a hooded figure wearing a black-faced, round-eyed gas mask. The figure tells him what Darren knows: that he stole a car, drove it recklessly while under the influence of drugs and killed a woman and her baby. His solicitor managed to get the case thrown out of court on a technicality so he has not paid for his crime. That, says the figure, cannot be allowed to happen.