"No one," the doctor answered, "can say what psychic force is capable of doing. Some scientists have started to explore, but it is still uncharted country. From certain places--I daresay you've noticed it--one gets an impression of peace and content; from others a depression, a sense of suffering. I think we have all experienced psychic force to that extent. Remember that this room has a history of intense and rebellious suffering. Some of it I have seen with my own eyes. Your father's fight for life, Katherine, was horrible for those of us who knew he had no chance. As I watched beside him I used to wonder if such violent agony could ever drift wholly into silence, and when we had to tell him finally that the fight was lost, it was beyond bearing." "If these men had been found dead without marks of violence," Graham said, "I might consider such a possibility, irrational as it seems." "Irrational," Doctor Groom answered, "must not be confused with impossible. The marks of a physical violence, far from proving that the attack was physical, strengthens the case of the supernatural. Certainly you have heard and read of pictures being dashed from walls by invisible hands, of objects moved about empty rooms, of cases where human beings have been attacked by inanimate things--heavy things--hurtling through the air. Some scientists recognize such irrational possibilities. Policemen don't." "Very well," Graham said stubbornly. "I'll follow you that far, but you must show me in this room the sharp object with which these men were attacked, no matter what the force behind it." The doctor spread his hands. His infused eyes nearly closed. "That I can't do. At any rate, Robert, this isn't wholly tragic to you. I don't see how any one could accuse you of aphasia to-night." "You've not forgotten," Bobby said slowly, "that you spoke of a recurrent aphasia." "That's the trouble," Graham put in under his breath. "He has no more alibi now than he had when his grandfather was murdered." Bobby told of his heavy sleep, of the delay in Katherine's arousing him. The doctor's gruff voice was disapproving. "You shouldn't have drunk that medicine. It had stood too long. It would only have approximated its intended effect." "You mean," Bobby asked, "that I wasn't sleeping as soundly as I thought?" "Probably not, but you're by no means a satisfactory victim. Men do unaccountable things in a somnambulistic state, but asleep they haven't wings any more than they have awake. You've got to show us how you entered this room without disturbing the locks. Now, Mr. Graham, we must comply with the law. Call in the police." "There's nothing else to do," Bobby agreed. So they went along the dingy corridor and downstairs. From the depths of the easy chair in which Paredes lounged smoke curled with a lazy indifference. The Panamanian didn't move.