They found the admiral at Natchez, and when Frank had reported his arrival, he was ordered to take his station at Gaines' Landing--a place noted for guerrillas--which they reached in safety. For two or three days, nothing worthy of note transpired, the rebels, if there were any about, being careful not to show themselves. One night, while Frank was walking the deck, arm-in-arm with his cousin, the officer on watch approached, and said, in a low voice: "Look there, sir! What kind of a craft is that?" Frank looked in the direction indicated, and an object about the size of a man's head could be dimly seen in the water, silently but rapidly approaching the vessel. It came from toward the nearest shore, and the thought that it was a torpedo instantly flushed through his mind. Taking the spy-glass from the quarter-master, he leveled it at the object, and could distinctly see that it was a human head, and that it belonged to some one who was an excellent swimmer, for he was making rapid progress through the water. "I don't see any torpedo there," said he, at length, handing the glass to his cousin, "for the fellow, whoever he is, is using both hands." Then raising his it voice, he called out, "Who comes there?" "A friend," was the scarcely audible reply. "Come on board here." "That's just what I want to do," answered the man, who, with a few more strokes, was near enough to be seized by the quarter-master--who had ran below with a lantern--and lifted upon the guards. "Who are you, and what are you doing here at this time of night?" asked Frank, as soon as the man had come on deck. "My name is William Striker," was the answer, "and I am an escaped Union scout." Frank took the lantern from the quarter-master's hand and held it up, so that he could obtain a good view of the man's face. He was certain he had seen it before, but could not remember where. "I have a better memory than you, sir," said the man at length. "I have seen you before. I met you in the trenches at Vicksburg." As the man spoke, he produced a bundle of wet papers, from which he selected one that he handed to Frank. It was the appointment of major, and addressed to William Striker, United States Scout. But this was no proof that the man was in reality what he professed to be, for Frank remembered that he had once passed himself off as Lieutenant Somers, of the rebel army, and had shown his appointment and orders to prove it. It was true that he wore the dress of a Union major, but that might have been obtained in the same manner that Frank once got his rebel uniform. There was something suspicious in a man's presenting himself on board the vessel at that time of night, and in so uncommon a manner. "Well," said Frank, "if you were in the trenches at Vicksburg, tell me something that happened there."