I'm a big fan of Updike--his Rabbit novels, especially--but I' still convinced that this is his best book.
The story concerns three days in the lives of George and Peter Caldwell, two residents of fictional Olinger, Pennsylvania. George is a high school science teacher, an endlessly compassionate man who is cursed with dangerously low self-esteem. Peter is his son, a developing artist who simultaneously loves and is exasperated with his father.
Interwoven with their story is the story of Chiron, "the noblest Centaur." Chiron's existence is one of suffering, due to a fatal wound he recieved at the hands of Hercules. Because of this affliction, he willingly gives up his life to save Prometheus, who is being punished by Zeus for the theft of fire. Throughout the course of the novel, it becomes apparent that George Caldwell is Chiron, a hero who suffers that those around him might live, and that Peter is Prometheus, an impetuous youth who dares to touch the face of God.
All of these elements combine wonderfully to create one of Updike's best, most compassionate, most complex, and most personal works. It's got all the humanity and spiritual yearning of ROGER'S VERSION or the Rabbit novels, but it's also got something those books don't: hope.