A misguided prank between two young brothers exposes one of them to a toxic parasite that cannot be treated on the USS Enterprise, but Dr. Crusher is able to stabilize his condition in a controlled environment in Sick Bay while the ship travels to a facility that can cure the boy. As Data escorts the older brother to visit him, Data suddenly stops and returns to the bridge, where, unseen by the crew, he triggers an alarm that forces the bridge to be evacuated. Captain Picard orders Data to transfer the controls to Engineering, but Data instead mimics Picard’s voice and locks the command of the ship to the bridge, directing the starship to an unknown planet. The crew discover Data’s lockdown, and disable the transporter’s site-to-site function to prevent Data from easily moving about the ship. Once the Enterprise is in orbit about the planet, he creates a programmed sequence of force fields to allow him to move from the bridge to the nearest transporter room without being stopped by security, and then beams down to the planet, leaving the Enterprise still under his lockdown. Picard orders his crew to attempt to override any parts of the ship’s control, while Dr. Crusher attempts to keep the infected boy stabilized.. via Wikipedia

Questions inspired by the episode:

• Does duty to family supersede duty to one’s morals?
• Are inherently ‘bad’ or ‘evil’ people just malfunctioning (sick)?