“Corporal of the Guard! Post Number Ten!”

This was the cry, in various intonations, that went ringing down the line in the darkness. As instructed, Ned, Bob and Jerry, being the nearest to the place of the alarm, went to render what aid might be necessary to the sentry who had first called. Meanwhile the corporal of the guard, rousing those whose duty it was to go out with him and see to the disturbance, was hastening to the scene.

As Ned, Bob and Jerry approached they heard some one saying:

“But I must have it! I tell you I must get it. It is exceedingly valuable, and you ought not to stop me.”

“Stop you! I’ve stopped you all right!” came the vigorous tones of Kelly, the sentry.

“But I must get through. I must!”

“And I say you must not! Trying to run the guard under my very nose; that’s what you were[208] trying to do. But I caught you! You’re a German spy—that’s what you are!”

“No, I assure you that you are mistaken,” came a gentle voice in answer. “I am only after some new specimens——”

Ned, Bob and Jerry gave a shout.

“It’s him, all right!” cried Jerry, enthusiastically if not grammatically.

“I thought it sounded like him,” added Ned.

“Hello, Professor Snodgrass!” called Bob. “It’s all right. Keep quiet. We’ll be with you in a minute!”

They raced up to the excited sentry, who stood holding a small, bald-headed man, at the same time flashing in his face a pocket electric lamp.

“Oh, it’s you, boys, is it?” asked the little man, who did not seem at all disturbed by the situation in which he found himself. “Well, I’m glad to see you. I just arrived, getting in rather late on account of a delayed train. I walked over, intending to visit you. I had no idea it was so late, but I am glad it is, for I have just seen some specimens of moth that only fly about this hour. I wanted to catch some but—er—this gentleman——”

Professor Snodgrass, for it was he, paused and looked at his captor.

“You’re right! I wouldn’t let you go chasin’[209] through the lines!” exclaimed Kelly. “Do you know him?” he asked the motor boys.

“He is a friend of ours,” declared Jerry. “We know him well. He is Professor Uriah Snodgrass, of Boxwood Hall, and what he says is true—he does collect moths and other bugs.”

“Sufferin’ cats!” cried Kelly. “And I took him for a German spy! I beg your pardon,” he went on. “My father was a professor in Dublin University, and I’m sorry I disturbed you. I’ll help you collect bugs when I’m off duty.”

“Thank you!” said Professor Snodgrass, as if it was the most natural thing in the world to get offers of assistance in this way. “I shall be glad of help. Ha! There is one of the late-flying moths now!” and he reached over and made a grab for something on the shoulder of the corporal of the guard, who had come running up.

“Here! None of that! What’s the idea! Disarm him!” cried the corporal, who was hardly awake yet. “Has he bombs on him?” he asked of Kelly.

“I guess it’s all a mistake,” the sentry replied. “I was patrolling my post, when I saw some one walking along, and seemingly picking things up off the ground. Or maybe, I thought, he was planting infernal machines. So I rushed over and grabbed him, and I yelled and——”

“I was only gathering bugs by ............