“What’s wrong?” Bud asked.
“Don’t know,” Tom replied in a puzzled voice. “I’d better check the tanks.” A moment later, after inspecting the pressure gauges, he turned a grave face to his companions.
“The tanks are empty!” Tom reported.
CHAPTER IV
A HELIUM MYSTERY
BUD sprang out of his seat and hurried aft to join the young inventor. “You mean the liquid helium leaked out?” he asked in alarm.
“It leaked out, all right,” Tom replied grimly. “The loading cock is wide open.”
“Good griefl How did that happen?”
Tom gave a worried shrug. “Maybe I got careless and opened it accidentally.
But frankly, I don’t even remember touching the tanks before we left the ship.
How about you two?”
Both Bud and Chow denied knowing anything about it. Chow, who was dripping with sweat and fanning himself as usual with his sombrero, added, “Mebbe it’s this broilin’ hot weather. Must’ve made the helium swell up an’ bust out.”
Tom shook his head. “The helium wouldn’t expand enough to force the loading cock!” He wondered uneasily if someone might have tam-29
30 ELECTRONIC RETROSCOPE
pered with the plane during their absence. “We’d better check out the whole ship to make sure nothing else is wrong,” he decided.
With Bud’s help, Tom hastily checked the jet engines, landing gear, instruments, and other parts. But the paraplane showed no other sign of sabotage.
“Okay. Now what?” Bud asked.
“Looks as if we’ll have to hike out of this jungle on foot,” Tom replied.
“What about the plane? You’re not going to abandon it here, are you?”