The Enterprise was seized by Balok's giant ship Fesarius, and Kirk's bluff about a substance called corbomite turned a deadly threat into peaceful first contact.
In 2266 the Enterprise destroyed a spinning warning buoy in an uncharted region and was then held by the huge Fesarius, flagship of the First Federation. Its commander, Balok, appeared on screen as a menacing figure and announced that the Enterprise would be destroyed for trespassing.
With no way to escape, Kirk bluffed that the ship carried corbomite, a material that would destroy any attacker. Balok hesitated, and when his small tug craft later appeared disabled, Kirk went to help. He found that Balok was a friendly being who had been testing the crew's intentions. Lieutenant Dave Bailey stayed with Balok as a cultural envoy.