‘All my life I have harboured a sneaking assurance that God, or whoever is in charge of these things, would not take me in mid-sentence,’ Bernice Rubens wrote, and her confidence was justified. When God, or whoever is in charge of these things, did take a writer in mid-sentence it was not Rubens but John Gregory Dunne. He was sitting in an armchair by the fire with a drink; his wife, the writer Joan Didion, was cooking dinner. ‘John was talking and then he wasn’t.’ Joan saw he was sitting motionless, his left hand raised. At first she thought he was joking. Then she realised he was dead. ‘Life changes fast. Life changes in an instant. You sit down to dinner and life as you know it ends,’ Didion realised, and the words became her oft-repeated refrain.