She went disturbedly into the other cabin. Calhoun drew a sample of blood from the insensitive area on Murgatroyd's flank. Murgatroyd submitted with complete confidence in the man. In ten minutes Calhoun had diluted the sample, added an anticoagulant, shaken it up thoroughly, and filtered it to clarity with all red and white corpuscles removed. Another Med Ship man would have considered that Calhoun had had Murgatroyd prepare a splendid small sample of antibody-containing serum, in case something got out of hand. It would assuredly take care of two patients. But a Med Ship man would also have known that it was simply one of those scrupulous precautions a Med Ship man takes when using cultures from store. Calhoun put the sample away and called Maril back and offered no explanation. She said; "I'll fix lunch." She hesitated. "You brought some food from the first Weald ship. Do you want it?" He shook his head. "I'm squeamish," he admitted. "The trouble on Dara is Med Service fault. Before my time, but still--I'll stick to rations until everybody eats." * * * * * He watched her unobtrusively as the day went on. Presently he considered that she was slightly flushed. Shortly after the evening meal of singularly unappetizing Darian rations, she drank thirstily. He did not comment. He brought out cards and showed her a complicated game of solitaire in which mental arithmetic and expert use of probability increased one's chance of winning. By midnight, ship-time, she'd learned the game and played it absorbedly. Calhoun was able to scrutinize her without appearing to do so, and he was satisfied again. When he mentioned that the Med Ship should arrive off Dara in eight hours more, she put the cards away and went into the other cabin. Calhoun wrote up the log. He added the notes that Maril had made for him, of Murgatroyd's pulse and blood-pressure after the injection of the same culture that produced fever and thirstiness in himself and later--without contact with him or the culture--in Maril. He put a professional comment at the end. "The culture seems to have retained its normal characteristics during long storage in the spore state. It revived and reproduced rapidly. I injected .5 cc under my skin and in less than one hour my temperature was 30.8 deg.C. An hour later it was 30.9 deg.C. This was its peak. It immediately returned to normal. The only other observable symptom was slightly increased thirst. Blood-pressure and pulse remained normal. The other person in the Med Ship displayed the same symptoms, in prompt and complete repetition, without physical contact." He went to sleep, with Murgatroyd curled up in his cubbyhole. The Med Ship broke out of overdrive at 1300 hours, ship time. Calhoun made contact with the grid and was promptly lowered to the ground.