That's Starlight's signal.

See that smoke?
The half-caste always sends that up--like the blacks in his mother's tribe, I suppose.' 'Any cattle or horses with them ?' said Jim.
'No, or they'd send up two smokes.

They'll be here about dinner-time, so we must get ready for them.' We had plenty of time to get ourselves or anything else ready.

In about four hours we began to look at them through a strong spyglass which father brought out.

By and by we got sight of two men coming along on horseback on the top of the range the other side of the far wall.