"I can't think of any others. Except, perhaps, a feeling of exhaustion after I've gone through what I've just finished." He closed his eyes as if to shut out the recollection. "Well," mused the Doctor, "we'll forget the physical symptoms. What happens to your individuality, your own consciousness, while you're suffering an attack?" "Nothing happens to it," said Nick with a suppressed shudder. "I watch and hear, but what _he_ does is beyond my control. It's terrifying--horrible!" he burst out suddenly. "Doubtless," responded Horker smoothly. "What about the other? Does that one stand by while you're in the saddle?" "I don't know," muttered Nick dully. "Of course he does!" he added abruptly. "I can feel his presence at all times--even now. He's always lurking, waiting to spring forth, as soon as I relax!" "Humph!" ejaculated the Doctor. "How do you manage to sleep?" "By waiting for exhaustion," said Nick wearily. "By waiting until I can stay awake no longer." "And can you bring this other personality into dominance? Can you change controls, so to speak, at will?" "Why--yes," the youth answered, hesitating as if puzzled. "Yes, I suppose I could." "Let's see you, then." "But--" Horror was in his voice. "No, Dr. Carl!" Pat interjected in fright. "I won't let him!" "I thought you declared yourself out of this," said Horker with a shrewd glance at the girl. "Then I'm back in it! I won't let him do what you want--anyway, not that!" "Pat," said the Doctor with an air of patience, "you want me to treat this affliction, don't you? Isn't that what both of you want?" The girl murmured a scarcely audible assent. "Very well, then," he proceeded. "Do you expect me to treat the thing blindly--in the dark? Do you think I can guess at the cause without observing the effect?" "No," said Pat faintly. "So! Now then," he turned to Nick, "Let's see this transformation." "Must I?" asked the youth reluctantly. "If you want my help." "All right," he agreed with another tremor. He sat passively staring at the Doctor; a moment passed. Horker heard Pat's nervous breathing; other than that, the room was in silence. Nicholas Devine closed his eyes, brushed his hand across his forehead. A moment more and he opened them to gaze perplexedly at the Doctor. "He won't!" he muttered in astonishment. "He won't do it!" "Humph!" snapped Horker, ignoring Pat's murmur of relief. "Finicky devil, isn't he? Likes to pick company he can bully!" "I don't understand it!" Nick's face was blank. "He's been tormenting me until just now!" He looked at the Doctor. "You don't think I'm lying about it, do you, Dr. Horker?" "Not consciously," replied the other coolly. "If I thought you were responsible for a few of the indignities perpetrated on Pat here, I'd waste no time in questions, young man. I'd be relieving myself of certain violent impulses instead." "I _couldn't_ harm Pat!"