And on the screen, a wireframe grid.

On the third day, he ran his integrated test build. A simple scene: a red ball, a blue ball, and a seesaw. Drop the red ball on the left side, the blue ball launches into a target. Simple physics. But with Core Crossing enabled, the player could branch at the moment of impact. In Branch A, the red ball was heavy. In Branch B, it was light. In Branch C, the seesaw was made of rubber.

Core Crossing wasn't just simulating physics. It was simulating alternate timelines . Every time an object interacted with its environment, the engine generated a quantum-style branch of possibilities, ran them all simultaneously, and let the user pick which branch to follow. The "core" was the root timeline. The "crossing" was the moment of choice.

Not a power glitch. A patterned flicker. Three long, two short. Like a signal.