“That’s certain,” was Billie’s reassuring comment, and, feeling sure that a few minutes’ search of the chaparral would reveal the missing animal, they started out hastily, on foot, not deeming it necessary even to mount their steeds.

For the next ten minutes they tramped through the chaparral, calling to each other as they went, but no sign of the mule could be found. Then they returned to the camp and mounted their horses, but, although this enabled them to see over the tops of the mesquite bushes that spread out for miles up and down the river, they could see nothing of the missing animal.

“There comes Don,” Billie at last sung out, as he caught sight of the returning horseman. “Maybe he can give us some advice.”

But Donald had no advice to give, except to scatter and search.

“I hate to say 'I told you so,’” laughed Donald, “because it was really my fault that I didn’t get a new riata before. I reckon now we might as well decide to stop here all right, for I can see we have our afternoon’s work cut out.”

Half an hour’s riding having revealed no sign of Bray, the boys again met at the camp.

“Haven’t you seen anything at all?” called out Adrian, as the boys came within hailing distance of each other.

“Yes,” replied Billie, “I saw a hacienda about three miles up the river. I knew Don spoke a little Mexican, so I came back to tell him, and ask if you didn’t think it would be a good thing to apply to the owner for help. Maybe some of the peons have run across Bray and driven him home.”

“Good idea,” said Adrian. “You fellows go up to the hacienda and I’ll stay here and look after the other mule and the camp. I’m glad Bray didn’t have his pack on, or we’d stand a chance of going hungry tonight.”

“Don’t mention such a thing,” laughed Billie. “The very thought of it fills me with despair.”