The Exile PART 1 LOS ANGELES 1 TWENTY YEARS LATER.   Amtrak Station, the desert community of Barstow, California. Tuesday, March 12, 4:20 A.M. John Barron crossed toward the train alone in the cool of the desert night. He stopped at car number 39002 of the Amtrak Su-perliner Southwest Chief, waiting as a mustachioed conductor helped an elderly man with bottle-thick glasses up the steps. Then he boarded the train himself. Inside, in the dim light, the conductor wished him good morning and punched his ticket, pointing him past sleeping passengers toward his seat two-thirds of the way down the car. Twenty seconds later he put his small carry-on bag into the overhead rack and sat down in the aisle seat beside an attractive young woman in sweatshirt and tight jeans curled up against the window, asleep. Barron glanced at her, then settled back, his eyes more or less on the car door through which he had entered. A half minute later he saw Marty Valparaiso come on board, give the conductor his ticket, and take a seat just inside the front door. Several moments passed, and he heard a blast of train whistle. The conductor closed the door, and the Chief began to move. In no time the lights of the desert city gave way to the pitch-black of open land. Barron heard the whine of diesel engines as the train picked up speed. He tried to picture what it might look like from above, the kind of aerial shot you might see in a movie--of a giant, half-mile-long, twenty-seven-car snake, gliding west through the predawn desert darkness toward Los Angeles. Copyright (c) 2004 by Allan Folsom Excerpted from The Exile by Allan Folsom All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.