Joe took a quick look in the rear-vision mirror. Behind them was a new 1957 Mercury, and at the wheel was a hatless, black-haired man who seemed intent on the back of Joe's car. The man was alone in the Mercury. "We're going pretty fast," said Joe. "Just because he's been behind us awhile doesn't mean he's following us. Now don't get to thinking every car is following us, and the Devil's behind every tree, waiting to spring out on us." "Slow down and see if he passes us," suggested Pearl. Joe lifted his foot very slowly off the gas pedal and the speedometer needle began dropping from 65 to 60, then down to 55, and slowly and steadily down to 40. The car behind made no move to pass, and Joe dropped the speed down to 30, then to 25. Still the Mercury clung to their rear. "He _is_ following us!" exclaimed Pearl. "Not necessarily," said Joe. "I've had drivers like this behind me many times. But we will soon find out if he _is_ following us." He tramped on the gas, and the car leaped ahead. In a moment he had the speed up to 70, and kept increasing it until they were hurtling along at 90. The Mercury stayed right behind them. Jimmy's voice came in his ear now. "Beat him, Daddy!" he said excitedly. "Race him good. He can't beat us!" "He could if he wanted to," muttered Joe to himself. He eased off on the gas again, and the needle dropped to 65 once more. Pearl was pale. "He's following us, isn't he?" she said more than asked. "I don't know yet," said Joe. "We'll find out in the town just ahead. I'm going to take a few turns ..." his voice trailed off. As they passed the city limits, Joe dropped his speed to well below the posted limit and watched for a stop light ahead. Finally, he saw one, and he timed his arrival. Abruptly, as he reached it, he shot the car through the amber light just as the red flashed on. The Mercury stopped for the red light, and as the image receded in the rear-vision mirror, Joe breathed easier. "He didn't go through the red light," he said. Pearl was watching. "The light's changing again," she said. "He's coming up pretty fast." Joe put on his right-turn light and made a normal turn at the next corner. The Mercury made the turn too. Joe made another right turn two blocks down. The Mercury made one too. "That settles it," said Joe. "He's following us all right." * * * * *