What Happened to the Robots?

To mankind, the fall of earth's robot society was a mystery. The island they inhabited, a giant waste processing facility in the middle of the pacific, continued to function. It was tended to by a force of giant lumbering robotic custodians.

Mankind had prospered much from their alliance with the robots. The planet was less polluted and the robot's scientific progress had garnered numerous technological advancements. The robot society was born of man's intellect but had surpassed it in under a hundred years, and then vanished two centuries later with no known explanation.