The small robot TIM-21 and his mechanical companions fight for survival in a universe where all robots are banned and hunted by bounty hunters. One day, they appear out of nowhere above the nine most important planets of the United Galactic Council and begin their work of destruction. The Harvesters, gigantic robots, reduce worlds to rubble and ash, and then disappear as suddenly as they arrived. Since then, the galaxy has lived in fear that the Harvesters will return. For no one knows where they came from or who built them. All other robots, developed by humans for various purposes, become targets of hatred and are ruthlessly hunted down and destroyed. However, many years after the attack, the machine code of the Harvesters is cracked, and the Council's scientists make a stunning discovery.