"Where are they?"
"They certainly came in here!"
"That is true—they did come in here," said Dave. "Perhaps they are in hiding."
The boys began to search around the cabin and presently the senator's son found a piece of a log that was loose. He gave a push and it rolled away, showing a dark hole, leading through some thick bushes and past some rocks.
"This is the way they went!" he shouted. "It's a clever outlet."
The passageway was so dark the boys hesitated for a moment about entering it. Then Dave caught up a firebrand and went in. Soon the others heard him shout from some distance behind the cabin.
"Come right through!" he called. "It's all right."
They went through and next found themselves under some tall trees. Beyond was an open space, and here the tracks of the two men were plainly to be distinguished. They led to the shore of the island and disappeared on the ice beyond.
"They've gotten away from us," said Henshaw, disappointedly. He was limping badly.
"How's the ankle?" asked Dave.