Tragedy is a word lightly used by journalists to describe a range of experiences, from minor inconvenience to preposterous catastrophe. But there is something epic about the scale of Joan Didion’s misfortune. Didion’s memoir, The Year of Magical Thinking, was a fiercely resonant account of how, as she put it, “Life changes in the instant. You sit down to dinner and life as you know it ends.” In December 2003 her adopted daughter, Quintana Roo, became seriously unwell. On December 30, Didion and her husband of 39 years, the writer John Gregory Dunne, – returned from visiting her in hospital. As Didion prepared dinner, Dunne suffered a fatal heart attack. Soon afterwards Quintana suffered a brain haemorrhage from which she never fully recovered. She died in 2005, aged 39, shortly after The Year of Magical Thinking was published. That book was an extended essay about grief, written swiftly and in the grip of recent anguish. Blue Nights is a more diffuse meditation on loss, motherhood, attachment and the fragility that has been a constant undertone in Didion’s writing. Quintana was adopted, but Didion is whimsical to the point of evasiveness about the circumstances of her adoption. On New Year’s weekend 1966, the Dunnes went to stay with friends to one of whom Didion “mentioned that I was trying to have a baby”. At which the friend, who was herself adopted, recommended an obstetrician, Dr Blake Watson. Three months later, there was their daughter. It is never quite explained why they couldn’t, or didn’t, acquire a child by the usual method. As for the name, “We had seen [it] on a map when we were in Mexico a few months before and promised each other that if ever we had a daughter, Quintana Roo would be her name… The institution that became spring break in Cancún did not yet exist. There were no bargain flights. There was no Club Med. The place on the map called Quintana Roo was still terra incognita.” It is, admittedly, very bad luck to call your daughter by a romantic name that later becomes a tourist destination (fortunate, perhaps, that the Dunnes hadn’t been visiting Marbella). But their inconsequential parenting style extended well beyond nomenclature. Before she was born, they had been planning a trip to Saigon. “That year,” Didion writes, “during which the American military presence in Vietnam would reach 400,000… was not widely considered an ideal year to take an infant to south-east Asia, yet it never occurred to me to adjust the plan. I even went so far as to shop for what I imagined we would need: Donald Brooks pastel linen dresses for myself, a flowered Porthault parasol to shade the baby… Only later,” she adds, “did I see that I had been raising her as a doll.” Like any parent, Didion recalls with searing poignancy the quirks and terrors of Quintana’s childhood – her vulnerability; her terror of a figure she called “the Broken Man”; her precocious sophistication; her anxiety about her adoption: “What if you hadn’t answered the phone when Dr Watson called?” she used to ask. “Once she was born I was never not afraid,” Didion writes. Which is what we all feel once our children are born. But Didion’s apprehension is of a different order. Partly it seems to spring from a sense that her own fragility may in some sense have trumped or eclipsed her daughter’s need for protection. But mainly the purpose of her book is to explore the sense of timor mortis from which all humans suffer, and writers especially. For Didion, the long twilights around the summer solstice are a poignant metaphor for the feeling. She writes that she gave her book its title “because at the time I began it I found my mind turning increasingly to illness, to the end of promise, the dwindling of the days, the inevitability of the fading, the dying of the brightness. Blue nights are the opposite of the dying of the brightness, but they are also its warning.” This is not, technically, as finished a piece of writing as The Year of Magical Thinking. Like the gloamings of its title, it is vague, insubstantial, impressionistic, elusive. At times it reads more like an incantation than the crystalline self-examination of its predecessor. Yet for all its tremulousness it has an indomitable quality: a steely willingness to recollect past happiness in present adversity – the deepest of all sorrows, according to Dante – which it is impossible not to admire. Jane Shilling’s memoir, The Stranger in the Mirror, is out in paperback in January