London is being haunted by a serial killer who is beginning to evolve. Victims are left at iconic city landmarks and in the garden squares of the east end. They are carefully displayed with a pear in one hand and their heart in the other. The streets of London are not paved with gold but covered in blood.

Sam Stirling is the psychologist building the criminal profile to help DCI Albert 'Smiley' Riley and his team apprehend him. If Sam is to succeed, he will need assistance from psychotherapist Emma Malone. But the killer has developed an unhealthy obsession with Sam and Emma catches his eye...

After another victim is discovered with one more disturbing clue, the case finally starts to make sense. But as Sam closes in, the killer reverses the roles.

Who is the profiler now?