* * * * * "That man!" Mary murmured. "He'd drive a saint out of his mind. If I wasn't so fond of him I'd quit. If anyone told me I'd fall in love with a pathologist, I'd have said they were crazy. I wish--" Whatever the wish was, it wasn't uttered. Mary gasped and coughed rackingly. Carefully she moved back from the bench, opened a drawer and found a thermometer. She put it in her mouth. Then she drew a drop of blood from her forefinger and filled a red and white cell pipette, and made a smear of the remainder. She was interrupted by another spasm of coughing, but she waited until the paroxysm passed and went methodically back to her self-appointed task. She had done this many times before. It was routine procedure to check on anything that might be Thurston's Disease. A cold, a sore throat, a slight difficulty in breathing--all demanded the diagnostic check. It was as much a habit as breathing. This was probably the result of that cold she'd gotten last week, but there was nothing like being sure. Now let's see--temperature 99.5 degrees, red cell count 4-1/2 million. White cell count ... oh! 2500 ... leukopenia! The differential showed a virtual absence of polymorphs, lymphocytes and monocytes. The whole slide didn't have two hundred. Eosinophils and basophils way up--twenty and fifteen per cent respectively--a relative rise rather than an absolute one--leukopenia, no doubt about it. She shrugged. There wasn't much question. She had Thurston's Disease. It was the beginning stages, the harsh cough, the slight temperature, the leukopenia. Pretty soon her white cell count would begin to rise, but it would rise too late. In fact, it was already too late. It's funny, she thought. I'm going to die, but it doesn't frighten me. In fact, the only thing that bothers me is that poor Walter is going to have a terrible time finding things. But I can't put this place the way it was. I couldn't hope to. She shook her head, slid gingerly off the lab stool and went to the hall door. She'd better check in at the clinic, she thought. There was bed space in the hospital now. Plenty of it. That hadn't been true a few months ago but the only ones who were dying now were the newborn and an occasional adult like herself. The epidemic had died out not because of lack of virulence but because of lack of victims. The city outside, one of the first affected, now had less than forty per cent of its people left alive. It was a hollow shell of its former self. People walked its streets and went through the motions of life. But they were not really alive. The vital criteria were as necessary for a race as for an individual. Growth, reproduction, irritability, metabolism--Mary smiled wryly. Whoever had authored that hackneyed mnemonic that life was a "grim" proposition never knew how right he was, particularly when one of the criteria was missing.