Night's Black Agents is the third in a series of contemporary crime novels which feature DI Gilbert Markham and his teacher girlfriend Olivia Mullen. When the serenity of St Cecilia's Church where Olivia regularly worships is shattered by a series of murders, some very ugly secrets are brought to light. DI Gilbert Markham, assisted by his loyal deputy DS George Noakes, faces one of his most disturbing investigations. Three victims meet a grisly end, and his girlfriend comes face to face with evil in an unexpected quarter, before Markham finally uncovers the chilling truth and unravels the mystery of St Cecilia's.