Mark is consumed with paranoia, fearful that his life is at risk and that the perpetrator is someone known to him. Mark feels his own death treading on his heels, breathing down his neck. To make matters worse, Detective Inspector Lejeune seems to be increasingly suspicious of him and Mark feels even more alone. He's determined to find a rational explanation because there has to be one : this is the 1960s not the Dark Ages. Past and present collide for Mark as his investigations uncover the ties between his first wife Delphine and the trio of "witches" (Sheila Atim, Kathy Kiera Clarke, Rita Tushingham) at Much Deeping, putting his relationship with second wife Hermia under great strain. Terrified, Mark becomes hell-bent on uncovering the nature of the witches' powers and their work at The Pale Horse. With each passing day, each disquieting moment, each tormented, terrifying night, Osborne's beliefs seem less fantastical and more plausible. Mark starts to believe in the craft, in the dark arts, in the witches peculiar skills. If they are truly as powerful as they seem, can they save him from his nightmares, before whoever wants him dead catches up with him? How far will he go to save himself?