"He doesn't see us either," Compton said hoarsely. He cried, "Hey, you! You! Listen! We're Earthmen. Visitors from space."
His voice was explosive in the silence. The man didn't look up. The Earthmen became aware of music seeping from the walls, music strange and hauntingly beautiful, played on incredible invisible instruments.
"I don't like this," Compton said. "I don't like it at all. Why are they ignoring us? Why?"
"Maybe they can't help it," Hinckley suggested. "Perhaps they actually can't see us or hear us. It's fantastic, but it's possible."
"I wonder," Parker mused. And before anyone could stop him, he struck the man across the face with a doubled fist.
"Parker!" Hinckley cried. "You fool!"
"That's a matter of opinion," Parker said steadily, rubbing his knuckles. "I found out what I wanted to."
The man had fallen beneath the blow, but recovered seconds later. There was a large red welt on his forehead, but neither he nor the woman took any notice of it.
"It's incredible," Compton said.
"Evidently we can affect them physically, even if not mentally," Hinckley said. "You do something like that again, Parker, and I'll shoot you. I've got the authority to do it, you know, and sometimes the urge."