An award-winning journalist's all-night vigil with a retired chimp performer named Roger blossoms into a whole new way to regard our fellow creatures as well as ourselves.

While researching a recent "New York Times Magazine" cover story about chimpanzees, Charles Siebert visited a retirement home for former ape movie stars and circus entertainers in Wauchula, Florida known as the Center for Great Apes. There Siebert encountered Roger, a twenty-eight-year-old former Ringling Brothers star who seemed convinced he knew the author from some other time and place. Haunted by Roger's response,...