He broke the heavy crowbar from the emergency wall chest. He twisted the heavy steel in the locking mechanism on the inner panel of the door. Bracing his feet against the door and drawing the heavy bar toward him, he strained desperately. He knew from his meandering around the ship that the locking device was only to insure the doors would not open accidentally. The muscles in his back and shoulders bulged so that the tunic he wore split down the back. He tugged until his muscles quivered with the strain. He should break loose now so he could open the door from the inside. But nothing happened. * * * * * Joe relaxed, stood back and wiped the sweat from his brow; the lack of food had weakened him. The locking mechanism should have given way. Once more he inserted the bar in the device. Once more he called on his wood-trained muscles. He tried desperately this time, exerting all the strength he could summon. Blackness threatened to engulf. Then as if in a dream, he heard the muffled cling! That meant the device had snapped. He fell to the floor, his breath coming in sobs. Then he quieted, lifted his body up, and twisted the wheel. It turned easily, and the door pulled open at his tug. He came out into the passageway to face Arden, gun drawn. Arden cursed softly: "Won't you stay put, Joe?" Joe shrugged. "You need me," he said. "Need you?" repeated Arden. "Need you to infect us so we can't get the ship going again." Joe watched Arden, then he said: "Arden, why not cure me; then I won't be dangerous and I can help?" "No." Arden's voice was flat. "I'm the only man on ship who knows how to give the treatment, and you're not getting any. Your life is forfeit for what you almost managed to do." "You won't stop me, now, Arden," Joe said. "You can barely see me now, and you're trying so hard to keep from vomiting out your guts. You've got the radio disease; why don't you cure yourself?" Joe moved back slowly; Arden's gun followed him hesitantly. "You," Arden said. "You did it. You gave it to me." The gun steadied. "No," Joe said. "You had it before I ever came aboard ship. But you didn't know it, did you, Arden? You're a carrier, and you came to the ship straight from your wife." Arden shook his head weakly. "I took the usual tests; it showed me free of it." "But you know the usual tests, Arden; you know you can't tell for sure until you get the nausea. And it acts at varying speeds with different people, doesn't it?" Arden's fingers whitened on the gun; and Joe leapt aside suddenly. The shot blasted out. Then the gun dropped from Arden's fingers and he fell forward on his face, retching. Joe lifted the fallen metal expert almost tenderly, and carried him toward the hospital room. When he brought his burden in, Joe saw Burnet sitting on the edge of the bed, slipping on his sandals. Doc Guetschow, one of the professor twins, was remonstrating with him, trying to keep him in bed.