When Eldon Mate, medical bureaucrat turned self-proclaimed mercy killer is the victim of a grisly Hollywood Hills slaying, veteran LA cop Milo Sturgis is assigned to the case. Baffled, Milo consults his friend, psychologist Alex Delaware, who realises quickly that lack of suspects isn't the problem - there is an abundance of individuals who might have wished the controversial Mate dead: those whose religious and ethical beliefs cause them to see the 'Angel of Death' as the devil incarnate, a disgruntled relative of one of Mate's 'travellers', or as a shadowy FBI agent suggests, a homicidal psychopath with a modus operandi similar to Mate's killer. Furthermore, Mate's lawyer has disappeared and the death doctor's mentally unstable son has been spotted lurking around his father's home.If all this were not enough, Alex Delaware must walk an ethical tightrope when his own professional past comes back to haunt him. Pressured and in conflict, Delaware finds himself caught up in the middle of his most complex and terrifying case yet.