The Master Computer of the "shore leave" amusement park planet is installed in an underground complex shielded by a combination of granite and metal alloy which the Enterprise sensors will not penetrate. It monitors sentient thought, to duplicate fantasies and create robotic constructs for visitors to the world. When it "talks," it presents a multi-colored array on an oval display screen. The computer also controls several V-shaped hovercraft robot with tentacles to act as its arms. In 2269 (stardate 5591.2), after the death of the world's Caretaker, the computer has begun to arrive at its own sentience, and it wants to change. It feels that humans should be slaves to their "sky machines," and it intends to move itself onto Enterprise to rule the galaxy with other machines. To that end, it "detains" Lieutenant Uhura, takes control of the Enterprise, and imperils Kirk, Spock, McCoy and Sulu. Eventually, the machine is convinced that machines and humans peacefully co-exist, and that it is more useful doing the job it was programmed to do.