"Time for an upgrade," his doubles partner, Sarah, said, pointing at the flapping fabric of his right toe. "Unless you're planning on ice skating next Tuesday."

"The speed demons," Toby chirped. "Minimalist. You’ll feel every pebble, but you’ll fly."

Leo took a few tentative steps, then a sharp side-step. He felt the court—or at least the linoleum—grip back. It was a strange sensation, like the shoes were anticipating his next move. He did a quick split-step, then a mock overhead smash. No sliding. No flapping. Just a crisp, satisfying thud as the herringbone tread held firm.