But some other customers entered the bar at this point, and the plotters sank their tones so low that the boys could hear no more.

CHAPTER XVI.
THE AUTO GONE.

“Harry!”

“What is it, Frank?”

“Get on your clothes. You, too, Bart Witherbee, and be sure to conceal the map of your mine carefully.”

“What be yer goin’ ter do, Frank?”

“Fool those rascals. There is no doubt they are going to the stable and try to disable our aeroplane.”

“I reckon we’ll fool ’em, Frank.”

“I hope so. We must make haste. Come on out through this window here. It leads onto a back porch. We can slip down a support without anyone seeing us and get round to the stable before they get up from their table. They’ll be in no hurry, for they think we’re asleep.”

“What are we to do, Frank?” asked Billy Barnes and Lathrop, who, with old Mr. Joyce, were evidently to be left behind.