And when he set out again he went straight on to the old stone hut where Injun Jim had camped.

The tepee was gone, burned down according to Indian custom after a death, as he had expected.

The herd of Indian ponies were nowhere in sight.
Hahnaga's brother, he guessed, had driven them off long ago.
Casey had worked out a theory, bit by bit, and with characteristic optimism he had full faith that it would prove a fact later on.

He wanted to start his search from the point where Injun Jim had started, and he had rather a plausible reason for doing so.
Injun Jim was an Indian of the old school, and the old school did a great deal of its talking by signs.

Casey had watched Jim with that pale, unwinking stare that misses nothing within range, and he had read the significance of Jim's unconscious gestures while he talked.