It will drive you up the wall, but do try to read this cracking novel. We are in familiar McEwan territory. Well-groomed professionals sip malt whisky and agonise eloquently over moral conundrums and temptations. The prose is as smoothly reassuring as a freshly mown lawn. And there are the two abiding preoccupations of McEwan these days: a bitter distaste for religion and the reach for something beyond glib reasonableness. When Fiona Maye, 59, a high court judge, finds – against the Catholic parents – for a hospital wishing to save a child joined at birth to a weaker sibling, who must be sacrificed if his brother is to live, her judgment is applauded as “elegant and correct”. With “masked surgeons pitched against supernatural belief”, there can be only