Islands in the Stream was assembled from Hemingway’s manuscripts by his widow and his publisher ten years after his death, and although the book has a certain unfinished quality, it contains most of the Hemingway ingredients. Like much of his fiction, Islands in the Stream is strongly autobiographical, but this last novel carries even more of the fears and fantasies of this major American writer.

The novel is divided into three separate books, held together mainly by the character of Thomas Hudson. Part 1, “Bimini,” is the longest and most successful of the three. Little happens: Hudson, a painter “respected both in Europe and in his own country,” works; his three sons from two earlier marriages (his third wife never appears) arrive for a summer vacation; they all swim and fish. The descriptions are often rich, the scenes humorous, and the focus is on feelings, particularly on Hudson’s largely unexpressed love for his sons: “He had been able to replace almost everything except the children with work and the steady working life he had built on the island.”

In the longest scene, Hudson’s middle son, David, battles a huge broadbill for hours, only to lose him at the last moment. (In several significant ways, the scene resembles the fight between Santiago and the giant marlin in The Old Man and the Sea, 1952.) In another scene, the boys play drunkards in a local waterfront bar, to the dismay of a group of American tourists. Yet one of the group turns out to be Audrey, an old friend of Hudson and of Roger Davis, and in the end Audrey and Davis leave the island together, and then so do the boys. The ending of book 1 is abrupt and shocking; Hudson gets a telegram: “Your sons David and Andrew killed with their mother in motor accident near Biarritz.”

Part 2, “Cuba,” takes place a few years later on the farm or finca where Hudson is living (although his wife is absent). It is during World War II, and Hudson is no longer painting; instead, he has armed his fishing boat (as Hemingway himself did at this time), and he and his crew hunt German U-boats off the Cuban coast. Yet much of the action of part 2 takes place in a Havana bar, where Hudson has gone on a break from his patrol duties. Something is bothering him: “He could feel it all coming up; everything he had not thought about; all the grief he had put away and walled out and never even thought of on the trip nor all this morning.” As the reader finally learns, Hudson’s son Tom has been killed in air action over Europe. Instead of talking about it, Hudson has long and rambling conversations with various bar patrons, including Honest Lil, until Tom’s mother unexpectedly turns up, and the two of them drive to the finca, make love—and then Hudson tells her that their son is dead (but not the true details of his death). The agony of this scene is relieved only when Hudson is called back for patrol duty. “Your boy you lose,” he tells himself. “Love you lose. Honor has been gone for a long time. Duty you do.”

In part 3, “At Sea,” Hudson and his ragtag crew hunt down and kill the survivors of a sunken German submarine, on some uninhabited section of the Cuban coast, but not before Hudson himself is mortally wounded. “We didn’t do so good, did we?” Hudson concludes.

The three parts of the novel are not tightly interconnected; each could stand as a...