"What's that?" demanded Noll, jumping up.
But Hal was in the aisle before him. Both hastened to the rear door.
"Here, laddy-bucks," called a brakeman grimly, "stay inside! It's healthier!"
"What's up?" demanded Hal, without pausing.
"Judging by the sound, the train is held up, laddy-buck. It's a bad business going outside if that's the case."
But at this instant the door was opened before Hal's face. Major Davis bounded into the car.
"Come with me, men," he called sharply. "You're not armed, are you?"
"No, sir."
Even at that exciting moment Hal did not forget his salute.
"Then keep behind me," ordered the major, drawing his revolver. "This is a mail train, and, as a United States officer, I can't allow an attempt to rob it pass without an attempt at a protest."