They had followed the well-established principles step by step in studying these incredible people, and nothing had come out as it should. In theory, the steps they had taken should have yielded the answer. They had come to a planet where an entire population was threatened with a dreadful disease. They had identified the disease, found and isolated the virus that caused it, and then developed an antibody that effectively destroyed the virus--in the laboratory. But when they had tried to apply the antibody in the afflicted patients, the response had been totally unexpected. They had stopped the march of death among those they had inoculated, and had produced instead a condition that the people seemed to dread far more than death. "Let's face it," Dal said, "we bungled it somehow. We should have had help here right from the start. I don't know where we went wrong, but we've done something." "Well, it wasn't your fault," Jack said gloomily. "If we had the right diagnosis, this wouldn't have happened. And I _still_ can't see the diagnosis. All I've been able to come up with is a nice mess." "We're missing something, that's all," Dal said. "The information is all here. We just aren't reading it right, somehow. Somewhere in here is a key to the whole thing, and we just can't see it." They went back to the data again, going through it step by step. This was Jack Alvarez's specialty--the technique of diagnosis, the ability to take all the available information about a race and about its illness and piece it together into a pattern that made sense. Dal could see that Jack was now bitterly angry with himself, yet at every turn he seemed to strike another obstacle--some fact that didn't jibe, a missing fragment here, a wrong answer there. With Dal and Tiger helping he started back over the sequence of events, trying to make sense out of them, and came up squarely against a blank wall. The things they had done should have worked; instead, they had failed. A specific antibody used against a specific virus should have destroyed the virus or slowed its progress, and there seemed to be no rational explanation for the dreadful response of the uninfected ones who had been inoculated for protection. And as the doctors sifted through the data, the Bruckian they had brought up from the enclosure sat staring off into space, making small noises with his mouth and moving his arms aimlessly. After a while they led him back to a bunk, gave him a medicine for sleep and left him snoring gently. Another hour passed as they pored over their notes, with Tiger stopping from time to time to mop perspiration from his forehead. All three were aware of the moving clock hands, marking off the minutes that the force screen could hold out.