It came in a plain brown wrapper, no return address - a tape recording of a horrifying, soul-lacerating scream, followed by the sound of a childlike voice delivering the enigmatic and haunting message:

'Bad love. Bad love. Don't give me the bad love...'

For child psychologist Dr Alex Delaware, the chant, repeated over and over like a twisted nursery rhyme, is the first intimation that he is about to enter a living nightmare. Others soon follow: disquieting laughter echoing over a phone line that suddenly goes dead, a chilling trespass outside his home, a sickening act of vandalism. A carefully orchestrated campaign of vague threats and intimidation rapidly builds to a crescendo as harassment turns to terror, mischief to madness.

Searching his memory for the phrase 'bad love', Alex recalls a symposium he attended over a decade ago commemorating the work of Dr Andres de Bosch who ran a clinic for troubled adolescents. But when he tries to contact the other delegates, Alex discovers a seemingly random series of violent deaths amongst them.

As he delves deeper into the history of the clinic, the escalating pattern of violence becomes inescapably clear. And if Alex fails to decipher the twisted logic of the stalker's mind-games, he will be the next one to die.