Stephen King’s latest novel is a time-travel fantasy about the assassination of John F. Kennedy. At almost 750 pages, 11.22.63 is drawn-out even by blockbuster standards. Critics have bemoaned its surfeit of period detail (bobby socks, Hula Hoops, big-finned cars). I rather enjoyed it. King, now an august-looking 64, is a writer of towering cleverness, whose fiction manages to appeal to a reading public both popular and serious.