"Lock it!" snarled Brooks.
When the men had secured the portal, Brooks turned and pushed Tom roughly along the passageway. A moment later they reached the control deck where Bull Coxine was hunched over his charts.
"Here he is, Captain," said Brooks. "The other two are sealed up in the air lock like sardines!"
Coxine nodded and faced Tom, a thin smile on his face. "I told you I would get the recognition signal, Corbett," he said. "And I will!" Coxine walked over to a large valve on the after bulkhead and tapped the needle indicator right beside it. Satisfied, he turned back to the cadet.
"In two hours," began Coxine, "we'll be within range of the Ganymede garrison and its radar. It takes exactly eight turns on this valve to bleed the air out of the air lock where your two buddies are. So, every fifteen minutes I'm going to ask you for the recognition signal, and every time you say no, I'll turn the valve once. By the time we get close enough to Ganymede to be picked up on their radar, you'll either have given me the signal or your buddies will be dead!"
Tom stood listening to Coxine, his blood boiling at the giant spaceman's cruelty. Suddenly he tore across the control deck and made a dive for Coxine's neck. But the big man met him coming on and with a powerful slap of his hand sent the boy sprawling back across the deck.
"You're a good man, Corbett," said Coxine, standing over the fallen cadet, "but you're a little man, and a good big man can lick a good little man any time!"
Brooks and the crewmen laughed loudly as Tom dragged himself to his feet.
"Well, do I get the signal?" demanded Coxine. "Or do your buddies get a little less air?"
Standing unsteadily on his feet, with four paralo-ray guns trained on his body, Tom thought quickly of Roger and Astro, alone in the darkness of the air lock, soon to be clawing their throats for air; of the merciless attack on the prison asteroid; of the helpless ships Coxine had looted. All these things and more flashed through the curly-haired cadet's mind as he weighed his life and the lives of his unit-mates against an attack that would devastate the small satellite of Jupiter. Tom could see through the pirate's demand for the recognition signal. Once inside the Ganymede radar screen, he could attack the Solar Guard garrison and wipe it out before it could raise a ship in defense.