Down the street in front of the Wernbergs' house they could see men getting into the two automobiles. Presently the whirr of the motors came to their ears and the two cars started. One came towards them and the other went in the opposite direction. "Which one shall we follow?" whispered Bob. "Let's follow the one going the other way." They rolled out of the driveway and started down the street. As they turned into the avenue the first car passed them, a gray roadster bespeaking power and speed in its every detail. Two men were seated in it. Bob and Hugh obtained a fleeting glimpse of them as they flashed by. The tail light of the car they intended to follow showed a dim, red spot far down the street. "Speed her up a little, Bob," urged Hugh. "We don't want to lose them." "We can't keep too close to them either," said Bob. "Besides, my thumb and forefinger are pretty sore from that fuse burn and it's hard to grip the wheel." "Mine are sore too," said Hugh. "Put on gloves." "I haven't any with me." "I have; take mine." Still watching the small red dot ahead of them Bob managed to slip on Hugh's right-hand glove. It was a great help to him in driving. "They've turned a corner," exclaimed Hugh suddenly. "Faster, Bob!" Bob pressed his foot on the accelerator and the car leaped forward as if it were a living thing. A moment later they reached the cross street and turned into it, peering anxiously ahead. The car they were following was still in sight. "Keep about two hundred yards in back of them," Hugh advised. "We mustn't lose them." "No, and we don't want them to get suspicious either." "They're turning another corner," exclaimed Bob after a few moments. "Speed it up now that they can't see us." Bob did so and they came to the corner just in time to see the car they were following pull up at the curb in front of a white stucco house. "Go ahead, Bob! Go ahead!" urged Hugh. "Don't turn!" Bob kept straight on. "What street was that?" he asked. "Elm Street." "Isn't that where the German on the bridge told Harold he lived?" "Why so it is," exclaimed Hugh. "I wonder what number that house is." "I don't know. Let's see, Howard Seeley lives on Elm Street, just the next block down; his number is eleven hundred and something." "The German told Harold he lived at twelve eighty-two, and I'll bet you that was the house." "Whew!" whistled Hugh. "I wonder if it was." "They probably went to find out why the bridge wasn't blown up to-night," said Bob. "Do you suppose that could be it?" "Maybe. We could have told them quicker if they'd come to us though," chuckled Hugh. "They'll probably give that fellow the mischief for failing." "They can't get at him if he's in jail." "That's so. Suppose we're called as witnesses at his trial? They'll learn that we spoiled their game and our lives won't be worth two cents." "Well, if those men are plotters we must prove it before the case even comes to trial."