On his screen, water caustics danced across ancient cobblestones. A fish the size of a cat swam past a submerged bakery. He tilted the phone, and the light shifted. He tapped to swing his sword, and a plume of bubbles erupted. The frame rate held at a silky 60fps. The phone was cool to the touch.

“No,” she said, tapping the screen. “You’re rendering things the player isn’t looking at . Your camera is always moving. But a phone is a window. What if the world only renders what’s inside the window? Everything else… a ghost.”

Leo looked down at his phone, sitting face-up on the table. The screen was dark, but he could still see the ghost of that first ugly tree—the one with the jagged polygons. He thought of Zara’s grin. He thought of all the kids with last year’s phones, waiting for a world they could hold in their hands.