"You see the same thing," retorted Dan.

"How do you know I do? Even if you knew that what I call red would not be green could you see through my eyes — even if you knew that, how do you know that I too am not a dream of yours?"

Dan laughed. "Of course nobody knows anything. You just get what information you can through the windows of your five senses, and then make your guesses. When they're wrong, you pay the penalty." His mind was clear now save for a mild headache. "Listen," he said suddenly. "You can argue a reality away to an illusion; that's easy. But if your friend Berkeley is right, why can't you take a dream and make it real? If it works one way, it must work the other."

The beard waggled; elf-bright eyes glittered queerly at him. "All artists do that," said the old man softly. Dan felt that something more quivered on the verge of utterance.

"That's an evasion," he grunted. "Anybody can tell the difference between a picture and the real thing, or between a movie and life."

"But," whispered the other, "the realer the better, no? And if one could make a — a movie — very real indeed, what would you say then?"

"Nobody can, though."

The eyes glittered strangely again. "I can!" he whispered. "I did!"

"Did what?"

"Made real a dream." The voice turned angry. "Fools! I bring it here to sell to Westman, the camera people, and what do they say? 'It isn't clear. Only one person can use it at a time. It's too expensive.' Fools! Fools!"

"Huh?"

"Listen! I'm Albert Ludwig — Professor Ludwig." As Dan was silent, he continued, "It means nothing to you, eh? But listen — a movie that gives one sight and sound. Suppose now I add taste, smell, even touch, if your interest is taken by the story. Suppose I make it so that you are in the story, you speak to the shadows, and the shadows reply, and instead of being on a screen, the story is all about you, and you are in it. Would that be to make real a dream?"