"The fellow burned matches like those used In the hut as already stated, and threw the sticks about. He left the electric apparatus out of order, and that is why it would not run this morning when the Major wanted to use it."
"Originally that might have been the reason," laughed the Captain, "but I have an idea that the boys—"
"Never mind that!" Ned said. "We are not supposed to know anything about it. For if the Lieutenant had been a willing member of the party, wouldn't he have taken charge of the motor boat and got the party away in it?"
"Oh, all right! Have your own way about it!" smiled the Captain. "Let us suppose, solely for the sake of argument, that the Lieutenant was taken prisoner and went away against his will. Does that prove that he was taken from the island?"
"I was coming to that point," Ned replied.
He then called the attention of the Captain to the food tins which lay scattered about.
"These tins," he said, "have been opened within a few hours, which shows that the intruders rested and waited here and ate their suppers, perhaps their early breakfasts also. There were several of them, as you will see by the number of tins opened. The party embarked here. You can see where the nose of the canoe struck the mud."
"I reckon, as I remarked before," the Captain said, "that you don't need any instructions as to the use of your eyes! And the gray matter back of them seems to know what to do with the material unloaded on it! What next?"
"About the Lieutenant going away voluntarily," Ned went on. "Now step down here to the river bank. You notice the footprints in the mud, close to the water's edge?"
"Yes; they are plain enough."