"What's that coming?" cried Nan, standing up in her stirrups to
look toward the rolling cloud.

"The wagons," said Rhoda. "See! The boys have got the mules on the
gallop. Their only chance is to reach the ranch."

"But can't we reach the house?" demanded Grace, trembling.

"I won't risk it--There! See that?"

The slate-colored cloud seemed to shut out everything behind the
flying wagons like a curtain. The breeze about the little cavalcade
had died away. But Rhoda's cry called attention to something that
sprang up from the site of the mule-drawn chuck wagons, and flew
high in the air.

"A balloon!" gasped Bess.

"A balloon your granny!" exclaimed Walter, tying the legs of the
antelope to his saddle pommel. "Go ahead, girls. I'll be right
after you."

"It was a wagon-top," explained Rhoda, twitching her already
nervous pony around. "They did not get it tied down soon enough."

"Then a big wind is coming!" Nan agreed.

"Come on!" shouted Rhoda, setting spurs to her mount.