Kelly Lightfoot, her not-too-serious peeve forgotten, had come back into the galley to listen to the radio exchange. The men got up from the table and Clay gathered the disposable dishware and tossed them into the waste receiver. "We'd better get rolling," Ben said, "those clowns could still be on the thruway, although they could have got off before the filters went up." They moved to the cab and took their places. The big engines roared into action as Ben rolled Car 56 back onto the police-way. Kelly finished straightening up in the galley and then came forward to sit on the jump seat between the two troopers. The snow had stopped again but the roadways were still slick and glistening under the headlights. Beulah rolled steadily along on her broad tracks, now cruising at one hundred miles an hour. The steady whine of the cold night wind penetrated faintly into the sound-proofed and insulated cabin canopy. Clay cut out the cabin lights, leaving only the instrument panel glowing faintly along with the phosphorescent buttons and knobs on the arms of the control seats. A heavy express cargo carrier flashed by a quarter of a mile away in the blue lane, its big bulk lit up like a Christmas tree with running and warning lights. To their right, Clay caught the first glimpse of a set of flashing amber warning lights coming up from behind in the green lane. A minute later, a huge cargo carrier came abreast of the patrol car and then pulled ahead. On its side was a glowing star of the United States Army. A minute later, another Army carrier rolled by. "That's the missile convoy out of Aberdeen," Clay told Kelly. "I wish our hit-runner had tackled one of those babies. We'd have scraped him up instead of those other people." The convoy rolled on past at a steady one hundred twenty-five miles an hour. Car 56 flashed under a crossover and into a long, gentle curve. The chronometer clicked up to 2100 hours and the radio sang out. "Cars 207, 56 and 82, this is Pitt Control. 2100 hours density report follows...." Pittsburgh Control read off the figures for the three cars. Car 82 was one hundred fifty miles ahead of Beulah, Car 207 about the same distance to the rear. The density report ended and a new voice came on the air. "Attention all cars and all stations, this is Washington Criminal Control." The new voice paused, and across the continent, troopers on every thruway, control station, checkpoint and relay block, reached for clipboard and pen.