He buried his victim alive. And now he's escaped from prison and is on the run in the city.
Fiona Henderson, the daughter of the victim, has descended into a world of silence following her mother's murder - and has suddenly gone missing. Next, the body of a homeless person is found among the rubbish in a deserted alleyway.
As DIs Wheeler and Ross investigate, more suspicious deaths occur and a pattern emerges: the victims are all homeless. And so the police are pitched against a killer who is hellbent on a mission to rid the streets of the vulnerable and dispossessed.
With their investigation taking them further into Glasgow's netherworld, Wheeler and Ross uncover a criminal class ruthlessly willing to exploit the disaffected and a city of double standards, where morality is bought and sold.
When the killer begins stalking DI Wheeler, she and Ross realise that the threat has become personal.