Midway through Joan Didion’s memoir Blue Nights, she recognizes tone as though it were a found object held in her hand— a photograph of her daughter Quintana Roo, who died in 2009. It’s not stoicism that keeps her from staring at it but more of a kind of nimbleness (or agility?) of mind, flipping through a book of sketches of when Quintana was three years old, of when she got married—the stephanotis woven into her braid—and ultimately, when she passed away.