it said. “You have attempted 847 questions. You have failed 583. Your ratio of understanding to guesswork is… inefficient.”

“Last question. The one you always skip. The one about the trains.”

Leo closed his eyes. He stopped trying to calculate . He started telling a story.

Frustration boiled over. He slammed the laptop lid shut. The room went dark. But not completely. The blue glow bled through the seams of the laptop, seeping into the corners of his room like a liquid ghost. Then, the screen flickered on by itself.

The train problem appeared, but now the trains were real—two ghostly locomotives rushing toward each other in the distance, one blue, one red.