"You know Rankin was on the post that was taken in last night. He had a letter come yesterday, and I took it out to him, and he told me of what a fine supper they were going to have, saying they had bought some eggs and a chicken of a boy."
"Jerusalem!" suddenly exclaimed the corporal, "that boy to-day walked to the rear some little distance—made an excuse for going; he might not have been such a fool as he looked."
"Thank you," replied Fred. "Corporal, I will be here a little after dark with a squad of men to help you keep watch. In the mean time keep a sharp lookout."
"That I will," answered the corporal. "Do you think that boy was a spy?" he then asked, with much concern.
"I don't know," answered Fred. "But such a thing is possible. But if any trouble occurs on the picket line to-night, it will be at this post."
That night Fred doubled the pickets on six posts which he considered the most exposed. But the extra men were to guard the rear instead of the front. The most explicit instructions were given, and they were cautioned that they were to let no alarm at the front make them relax their vigilance in the rear. Thirty yards in the rear of the post where he was to watch Fred had noticed a small ravine which led down into a wood. It was through this ravine that he concluded the enemy would creep if they should try to gain the rear of the post. Fred posted his men so as to watch this ravine. To the corporal who had charge of the post, he said:
"My theory is, that some one comes up to your sentinel, and attracts his attention by pretending to be a friend, or perhaps a deserter. This, of course, will necessitate the sentinel's calling for you, and naturally attract the attention of every man awake. While this is going on, a party that has gained the rear unobserved will rush on you and be in your midst before you know it, and you will be taken without a single gun being fired."
The corporal and his men looked astonished.
"Zounds!" said one, "I believe it could be done."