The woman falls back against the wall, clutches a pistol in trembling hands. "Whoa," the man says, holding up his hands. "Whoa, okay. Is there a problem?"
"What is nine plus four?", she asks.
"What?"
"When I'm dreaming." she says, as if half to herself. "That's how I tell if people are real or not. You can have conversations with people in dreams, but if you ask them math problems they can't solve them, not even simple ones. So maybe those… maybe those things work the same way. If you're one of them maybe you won't be able to answer. What's nine plus four."
"It's… thirteen." he says hesitantly.
"What's eight plus three." she says, her shaking unabated.
"…Eleven." he says, smiling, not unkindly.
"What is the seven hundredth prime?"
"5,279." he replies without hesitation.
The pistol fires.
