Could a warped mind hope to escape from such a dilemma? Was there any possible way of making sure? No, not if he had actually cracked up. But supposing he hadn't. Suppose he had just passed for an instant over the borderline, as a result of strain, of abnormal circumstances, and was now completely rational again. In that case, proof would help. Proof could convince him that at least a part of what had happened had been real, that he had not been hallucinating continuously for days. If he could prove conclusively that he had not been hallucinating when he had climbed through the grate, Helen Ramsey's presence beyond the grate would be pretty well established. Even an insane man does not abandon all logic when he performs a complicated act. He is not likely to ascend a ten foot wall and climb through a grate in pursuit of a complete illusion. Oh, it _could_ happen.... Possibly it had happened many times in hospitals for the incurably insane. But somehow he could not believe that it had happened in his case. Right at this moment he was certainly not in an abnormal state of mind. How could he be when he was able to think so logically and consistently? Being sane now, or at least having the firm conviction that he was sane, would enable him to retrace what had happened step by step. What he were to retrace it in reality ... until he came to the grate? If the grate had been ripped out, the torment and uncertainty in his mind would vanish. He would be free then to move against Clement, to unmask and expose him for the scoundrel he was. Free? The very thought was a mockery. He was free for twenty feet in either direction, free to shout and summon the guard. But beyond that.... Corriston sat up straight. Free to summon the guard. Free to summon a man he had dropped to the floor with two quick, decisive and totally unexpected blows. But if he did summon the guard, what then? Could he be doubled up with cramps--the old prisoners' dodge? "Get me to a doctor. I think I'm dying." Hell no, not that. It was mildewed even on the face of it. The guard wouldn't be that much of a fool. He'd whip out a gun, and slash downward with it at the first suspicious move on the part of a man he hated. Was there any other way? Perhaps there was ... a quite simple way. Why couldn't he simply ask the guard to step into the cell and request permission to talk to him? He would plead urgency, but do it very casually, arouse the man's curiosity without antagonizing him too much. No need to be crafty, await some unlikely opportunity, or anything of the sort. Simply overpower the man--straight off, without any fuss. It had happened before, but that very fact would make the guard contemptuous, more than ever convinced that the first time he hadn't really been taken by surprise at all. His pride would make him want to believe that. He was the kind of man who could rationalize a humiliating defeat and blot it completely from his memory.