He slipped quietly off his bed. Fortunately the night was warm, and not like the preceding one, when they had shivered in their pajamas. So he crept over toward the double doors.
As Frank bent his head close to the rough wood in order to listen he felt the door quiver. It went through him like a shock of electricity that some one was trying to see if the entrance to the hangar was kept locked, since there was nothing in sight outside to indicate the fact.
Could it be Puss Carberry and his shadow, coming back again to attempt further destruction? Frank had another suspicion flash through his brain that gave him more of a shock than this first thought. The two robbers who were said to be in hiding somewhere close by—might they not have conceived the idea of stealing the completed aeroplane of the Bird boys, and in this fashion making an escape, outwitting the officers of justice, who would never dream of a flight through the air?
He listened further. They seemed to be whispering together again, though he was quite unable to catch a single word of what was said. But he fully believed that if his last thought proved to be the truth these desperate men would not give up a cherished scheme because of such a little obstacle as a barred door.
Then his first duty must be to arouse Andy, and without making any noise, if it could be accomplished. After that they would have to adapt their movements to circumstances.
So Frank cautiously made his way back to the cot where his cousin was peacefully slumbering, possibly dreaming of future triumphs that would fall to the portion of the Bird boys when they became masters of the air.
CHAPTER XI.
THE AEROPLANE THIEVES.
“Sh!”
Andy would have undoubtedly cried out on being so suddenly aroused by a shake, only that Frank hissed in his ear; and also held a hand over his mouth, so that he could not utter a sound.
He immediately put out a hand and touched Frank on the arm. It was intended to reassure the other, and convince him that the sleeper understood.