Yet here we are—and here comes “Shadow Ticket” (Penguin Press), the first new work by Pynchon in a dozen years. Although the author is eighty-eight years old, his intellect, at least on the evidence of this book, remains undiminished, which is to say, it is still panoptic, exciting, abstruse, distractible, and, for good or ill, unrestrained. But, if his powers are not dulled, neither are they pointed; even if you squint, it’s difficult to determine whether “Shadow Ticket” is a commentary on our current era—or, anyway, more of a commentary than, say, “Gravity’s Rainbow,” which was published half a century ago.