Chelsea Smile (Hennessey and Yellich Mysteries)

Five years after Duncan Percival is rendered a vegetable after a vicious attack, he finally dies. DCI Hennessey and DS Yellich are brought in to investigate what is now a murder case. As they delve deeper, the detectives are drawn into Yorks criminal underworld where grasses are punished and the gruesome Chelsea Smile is the favoured method of retribution...