Darkness came on, and still they rode along. Their speed was little better than a walk, and it was well that Hal had decided to discontinue his reckless driving.
From ahead, a sudden red glare went up to the sky, followed almost instantly by a report like that of a thousand cannons. The locomotive came to a stop with a jolt as Hal applied the brakes.
“What’s up now?” demanded Chester.
“I don’t know; but that explosion sounded to me as if there were something wrong ahead. I wouldn’t be surprised if the Germans had dynamited the bridge.”
“By George! I believe you are right,” exclaimed Chester. “I wouldn’t have thought of it, and if I had been in your place at the throttle the chances are we would have gone over if such is the case.”
“Well,” said Hal, “I’ll climb down, take a walk ahead and investigate.”
“I’ll go with you,” declared Chester.
“No, you won’t. You stay here and watch the engine.”
“You are right, as usual,” said Chester. “But don’t be any longer than you can help.”