Skolnik's voice pulled itself back from shivering pieces and went on, "Doc's lying on the floor ... and his voice is awful ... and the muscles in his face and arms and all over him are jumping and ... oh, Captain...." "Go on," Caffrey said savagely. "Go on!" "... and he's screaming, Captain, and we can't stop him...." Caffrey was out in the hall before the last syllable was uttered. The bulkheads spanged open as he kicked them. His feet slap-slapped frantically and when he was two sections away and one deck above Doc's quarters, he heard the screaming. It rose and shrilled and howled and made him more afraid than he had ever been in his life. The carefully acquired veneer of toughness shredded away like cheap cotton candy that was eaten at a Terran carnival and dissolved to nothing in the mouth. The eighteen crewmen of the ship were in the hall, milling and twisting their caps in their hands. Skolnik stood with his back to the wall. He had vomited on the floor and now he was crying. Caffrey was sicker when he smelled the bitterness, but he shoved at the crewmen. They stumbled against one another like dumb animals. Their faces belonged to little boys on dark nights when they walked home alone. They seemed to resist Caffrey's efforts, and he clubbed at them, the breath tearing in and out of his chest. Finally, he stood with his hands on the edge of the cabin door. * * * * * His hands had been sweating, but now he felt, actually felt, the wave of cold sweep through his fingers, up his arms. Doc was on the floor, like Skolnik had said. His scream made an endless mad tune above the engine rumble. His body was lifted from the floor, jerked, twisted, thrown back down again like some fantastic, jiggling marionette on strings. [Illustration: _Doc was on the floor. His screams made an endless, mad tune above the engine rumble._] "Doc," Caffrey called, "Doc, listen, it's me, Cap." The screaming slobbered into nothing. Doc's hands clutched at the iron frame of his bunk. They held there while the rest of his body was convulsed and pulled into insane contortions. "Infected," Doc said, forming his words into a shriek. "I got it from the child ... we're all infected ... all ... we'll infect Mars ... spread ... spread ... _spread_...." The last word went up and up like the ship's takeoff siren. Doc struggled to hold onto the bed but his body went jerking away across the floor. Dillman peered over Caffrey's shoulder. The big man spoke very softly. "Go back to my cabin. Get my gun. Hurry." Dillman hesitated, then ran. Caffrey stood fascinated watching the devil's dance of the diseased man. Finally, something cool and hard was placed in his hand. The scream tore at his eardrums.