But about Bruckian anatomy, physiology or biochemistry, the little emissary would tell them nothing. He seemed genuinely frightened when they pressed him about the physical make-up of his people, as though their questions were somehow scraping a raw nerve. He insisted that his people knew nothing about the nature of the plague that had stricken them, and the doctors could not budge him an inch from his stand.

But a plague had certainly struck.

It had begun six months before, striking great masses of the people. It had walked the streets of the cities and the hills and valleys of the countryside. First three out of ten had been stricken, then four, then five. The course of the disease, once started, was invariably the same: first illness, weakness, loss of energy and interest, then gradually a fading away of intelligent responses, leaving thousands of creatures walking blank-faced and idiot-like about the streets and countryside. Ultimately even the ability to take food was lost, and after an interval of a week or so, death invariably ensued.

Finally the doctors retired to the control room for a puzzled conference. "It's got to be an organism of some sort that's doing it," Dal said. "There couldn't be an illness like this that wasn't caused by some kind of a parasitic germ or virus."

"But how do we know?" Jack said. "We know nothing about these people except what we can see. We're going to have to do a complete biochemical and medical survey before we can hope to do anything."

"But we aren't equipped for a real survey," Tiger protested.

"We've got to do it anyway," Jack said. "If we can just learn enough to be sure it's an infectious illness, we might stand a chance of finding a drug that will cure it. Or at least a way to immunize the ones that aren't infected yet. If this is a virus infection, we might only need to find an antibody for inoculation to stop it in its tracks. But first we need a good look at the planet and some more of the people—both infected and healthy ones. We'd better make arrangements as fast as we can."

An hour later they had reached an agreement with the Bruckian emissary. The Lancet would be permitted to land on the planet's surface as soon as the doctors were satisfied that it was safe. For the time being the initial landings would be made in the patrol ship's lifeboats, with the Lancet in orbit a thousand miles above the surface. Unquestionably the first job was diagnosis, discovering the exact nature of the illness and studying the afflicted people. This responsibility rested squarely on Jack's shoulders; he was the diagnostician, and Dal and Tiger willingly yielded to him in organizing the program.

It was decided that Jack and Tiger would visit the planet's surface at once, while Dal stayed on the ship and set up the reagents and examining techniques that would be needed to measure the basic physical and biochemical characteristics of the Bruckians.

Yet in all the excitement of planning, Dal could not throw off the lingering shadow of doubt in his mind, some instinctive voice of caution that seemed to say watch out, be careful, go slowly! This may not be what it seems to be; you may be walking into a trap....