When an armed man massacres several people in central London, Claudine witnesses the whole thing. To her horror, one of the victims is her brother, Jethro. Riven by grief, Claudine retreats to the family home in the Fens, which is where the police find her. She is left reeling when they tell her Jethro orchestrated the attack. Why would a gentle, if troubled, middle-aged man cause such bloodshed – and why would he include himself in the list of victims? The truth could lie in Jethro's research on a mediaeval cult. If Claudine can't solve the mystery in time, more people will die... and the darkness will claim her too. This twisty, unrelenting thriller is perfect for fans of , , and , using themes of grief to explore how people are never as straightforward as they seem. 'Intelligent crime fiction at its very best, cleverly plotted with a scorching climax.' 'Staggeringly good.' Reviews for D.L. Mark: 'Mark is an extraordinary talent – one of the best in the business. I adore how he writes.' 'Dark and compelling with characters you will never forget.' 'Mark is a wonderfully descriptive writer.' 'Mark's books are always taut, intelligent page-turners.'