"I have not time to explain matters to you now, for you had better go inside the Fort as soon as you can. He gave me a letter—"
"Aw! Get out," said the Lieutenant again. "You have been listening to some of Cyrus's stories, and he has made you believe that you have some sort of medicine that will protect you from their bullets. Come on, all my men, and we will go to the Fort while you are thinking about it. It may be that we will find some Sioux who will give us a letter—"
Guy and his men were all inside the tower by this time, and they closed the heavy door and bolted it, thus shutting off what else the officer was going to say in regard to that letter. They heard his laugh ringing on the outside, and through the loopholes saw him march away toward the Fort.
"Did that Sioux really give you a letter, sir?" asked one of his men, as they climbed the rude stairway to reach the top. "Who was that letter directed to?"
"I have not time to go into all the particulars now," said Guy, as he leaned on the walls on the top of the tower and looked after the wagon train and its escort. "You will hear all about it when you get back to the Fort. Is that flag all ready? Lay aside your guns, but have them handy, and keep a close watch on that train."
As Guy had never been in the tower before, he looked around him with no little curiosity. The ridge leading from the Fort to where good timber was to be found was in plain sight, and every move the wagon train made could be distinctly seen. The Fort stood considerably lower than this tower, but there were several mountain howitzers in the Fort which had been trained on this ridge. The gunners, however, could not shell the ravines on each side of it with any accuracy, and Guy saw at once, with a soldier's eye, that about a mile beyond them was a splendid place for an ambush. His heart fell when he noticed it, but he did not say anything to his men about it.
"The Sioux have got the better of us or I shall miss my guess," said Guy, hauling his binoculars from its case and settling himself on a log which had been cut off sufficient to serve for a seat. "If they make their attack from one of those ravines, we cannot see it until we are right on to it, and they will clean us out as sure as shooting."
Having observed the train and seen that it was all right so far, Guy began an examination of the tower to see what chances he had for making a successful resistance in case he were assaulted. He was more than satisfied with it. The tower was built of green logs which could not be set on fire by the hostiles at any reasonable distance, and was well supplied with loopholes, so that a company of determined men could hold their own until assistance could reach them from the Fort. While he was thus engaged one of his men called his attention to a faint sound which he heard coming from the further end of the ridge.
"It sounded to me like a war whoop, sir," said he. "It could not be that. Yes, sir, that is what it is."
In an instant Guy Preston was on his feet with his glass pointed toward the wagon train, and saw something that he hoped he never would see again—a hundred Indians, all well mounted and armed, were making a charge on the wagon train's escort. Where they came from was a mystery, but they were there, and the faint yells which struck his ears now and then showed that they were out there for no good purpose.