When John Steinbeck was at work on his "The Acts of King Arthur and His Noble Knights" in the middle and late 1950's, he hoped it would be "the best work of my life and the most satisfying." Even in its original form, the project was enormous—translation of the complete "Morte d'Arthur" of Sir Thomas Malory; and the project soon became still more difficult, not translation but a complete retelling—rethinking—of the myth. Steinbeck finished only some 293 uncorrected, unedited pages, perhaps one-tenth of the original. Even so, the book Steinbeck's friend and editor Chase Horton has put together is large and important. It is in fact two books, Steinbeck's mythic fiction on King Arthur's court, and a fat, rich collection of letters exchanged between Steinbeck, Horton and Elizabeth Otis, Steinbeck's agent. The first is an incomplete but impressive work of art; the second, the complete story...