Imagine a young man on his way to a less-than-thirty second event — the loss of his left hand, long before he reached middle age. The Fourth Hand asks an interesting question: “How can anyone identify a dream of the future?” The answer: “Destiny is not imaginable, except in dreams or to those in love.”

While reporting a story from India, a New York television journalist has his left hand eaten by a lion; millions of TV viewers witness the accident. In Boston, a renowned hand surgeon awaits the opportunity to perform the nation’s first hand transplant. Meanwhile, in the distracting aftermath of an acrimonious divorce, the surgeon is seduced by his housekeeper. A married woman in Wisconsin wants to give the one-handed reporter her husband’s left hand—that is, after her husband dies. But the husband is alive, relatively young, and healthy.

This is how John Irving’s tenth novel begins; it seems, at first, to be a comedy, perhaps a satire, almost certainly a sexual farce. Yet, in the end, The Fourth Hand is as realistic and emotionally moving as any of Mr. Irving’s previous novels. The story offers a penetrating look at the power of second chances and the will to change.