 While visiting a Starbase, the Enterprise is hijacked by Mr. Spock, leaving Captain Kirk but taking Fleet Captain Pike, the ship s former commander, recently crippled by an accident. The destination: Talos IV, a planet off limits by Federation order since the Enterprise encountered it years ago. When Kirk and the Starbase commander intercept the Enterprise, Commodore Mendez convenes a court martial for Spock s apparent treachery. Spock s only defense is a video stream from Talos IV of Pike s imprisonment by the Talosians, a dying race who use their power of illusion to lure "specimens" into captivity and then study their reactions to simulated events. As they view the ordeal from the Enterprise s past, Kirk and the court must decide whether to convict Spock of mutiny.