Powers has gathered all the surviving correspondence between the two novelists, which reveals how these mutual admirers became devoted friends near the end of James's life. Though very few letters survive from Wharton's side, she's still a strong presence here as James admires her travels and projects, his awe alternating with delicious irony. Though full of references to her failing marriage and his failing health and hopes, his letters are buoyed up by a playful wit.