The other wife

"William and Mary live in Wales and have been married sixty years with four children and five grandchildren. William is a celebrated surgeon, Mary a devoted wife. Both are strong believers in right and wrong. William and Olivia have been together twenty years and share a house in London, enjoying the theatre and restaurants and playing tennis every week. Only one of these stories can be true - but which one? This is the question that confronts clinical psychologist Joe O'Loughlin when his father is brutally attacked and left for dead. Summoned to the hospital, Joe discovers a stranger at William's bedside, an elegantly dressed woman, covered in his blood. 'Who are you?' he asks. 'I'm his other wife.'"--Publisher's description.