The Black Doctor lay silent for a moment, staring at Dal. Then the fear seemed to fade from his face, and the anger disappeared. With a great effort he moved his head to nod. "All right, son," he said softly. "Do the best you know how." * * * * * Dal knew from the moment he made the decision to go ahead that the thing he was undertaking was all but hopeless. There was little or no talk as the three doctors worked at the operating table. The overhead light in the ship's tiny surgery glowed brightly; the only sound in the room was the wheeze of the anaesthesia apparatus, the snap of clamps and the doctors' own quiet breathing as they worked desperately against time. Dal felt as if he were in a dream, working like an automaton, going through mechanical motions that seemed completely unrelated to the living patient that lay on the operating table. In his training he had assisted at hundreds of organ transplant operations; he himself had done dozens of cardiac transplants, with experienced surgeons assisting and guiding him until the steps of the procedure had become almost second nature. On Hospital Earth, with the unparalleled medical facilities available there, and with well-trained teams of doctors, anaesthetists and nurses the technique of replacing an old worn-out damaged heart with a new and healthy one had become commonplace. It posed no more threat to a patient than a simple appendectomy had posed three centuries before. But here in the patrol ship's operating room under emergency conditions there seemed little hope of success. Already the Black Doctor had suffered violent shock from the damage that had occurred in his heart. Already he was clinging to life by a fragile thread; the additional shock of the surgery, of the anaesthesia and the necessary conversion to the heart-lung machine while the delicate tissues of the new heart were fitted and sutured into place vessel by vessel was more than any patient could be expected to survive. Yet Dal had known when he saw the second cardiogram that the attempt would have to be made. Now he worked swiftly, his frail body engulfed in the voluminous surgical gown, his thin fingers working carefully with the polished instruments. Speed and skill were all that could save the Black Doctor now, to offer him the one chance in a thousand that he had for survival. But the speed and skill had to be Dal's. Dal knew that, and the knowledge was like a lead weight strapped to his shoulders. If Black Doctor Hugo Tanner was fighting for his life now, Dal knew that he too was fighting for his life--the only kind of life that he wanted, the life of a physician.