“Let’s try something different now,” the man finally said.

It started easy enough. Strange new shapes appeared on the screen. They weren’t gears, exactly, but they had spikes and grooves and jutting angles that let them fit together the way gears do. The man bent near the tube again and showed him how by manipulating a control ball near his hand, Evan could change the images on the screen. He could move them.

“These are three-dimensional puzzles, Evan,” the man said. “Your teachers tell us that you are very good at puzzles. Is that true?”

“I’m pretty good,” Evan said, but he’d never seen puzzles like this before.

He experimented, moving one image toward another, turning it so their grooves lined up. The images merged, and a chime sounded.

“Good job, Evan,” the man said, and walked back to his computer. “Now we’ll try some harder ones.”

New, complex shapes appeared on the screen. Evan had to rotate each one completely to get a good look, because all the sides were different. He moved them together. He found where they fit. The machine chimed.

“Good, Evan.”

The solutions came easily. The complexity of the spatial configurations pulled him in, focused him to a fine point of concentration. Something was happening in his head; he felt it, as if some hidden green part of him was warming in the sunshine. The world around him retreated, became remote, irrelevant.

He no longer noticed the tube, or the computer, or the room with its four white walls and four white coats. There were only the puzzles, one after another, in a blur of shapes he manipulated with the controls at his fingertips.

He worked puzzle after puzzle, listening for the chime when he got them right.

Then the screen was empty, jarringly empty, all at once. It took him a moment to come back to himself enough to speak.

“More,” he said.