All the time the trail kept getting fresher.
“We’re catching up on them,” cried Rob. “It’s slow but sure; we’re catching up.”
Presently they stood in the space under the tall trees where Tubby and Fred had paused and where the San Blas Indians had surprised them. Rob, like a pointer dog, went rapidly hither and thither, crouched low, looking for the tiny signs which mean so little to an untrained and so much to a carefully educated eye.
Suddenly he gave a sharp cry. It brought Mr. Mainwaring to his side in an instant.
“Look, sir! Here in this soft earth! The print of bare feet! Very small bare feet! What does it mean?”
“Indians!” exclaimed Mr. Mainwaring, his face working. “The trail ends here, Rob. Oh, my poor boy! My poor boy!”
And, quite overcome, Mr. Mainwaring sank down on the same log on which, had he but known it, his son Fred had collapsed but a short time before. It was a long time that he sat there with his head buried in his hands, and when he raised his face Rob saw that it was white and strangely drawn, but full of determination.
“What are we to do, sir?” demanded Rob. “I’m afraid that, as you say, there is no doubt they have been carried off; but luckily, I see no signs of a struggle. Perhaps there is hope.”
Mr. Mainwaring had said nothing and Rob had not told him of his discovery of a spear that still stuck in the tree into which it had darted quivering above Tubby’s head. He could not find it in his heart to increase Mr. Mainwaring’s distress, and, agitated as he himself was, Rob had still thoughtfulness enough not to add to another’s burdens.