"Caught in the cooling fan housing," Rocco said, handing the rock to the stunned driver. "The sensors don't care about a pebble. But the machine does." The young man reached for his wallet. "What do I owe you?"
"It’s making a sound," the suit said, waving a hand vaguely at the car. "Caught in the cooling fan housing," Rocco said,
Rocco leaned over the hood, closing his eyes. He didn’t plug in a scanner. He just listened. He heard the rain on the corrugated roof, the distant hiss of traffic, and then—underneath the sterile hum of the battery—a tiny, rhythmic clink . "Caught in the cooling fan housing