As Kirk, Uhura and Chekov are about to be beamed to the planet Gamma 2, they unexpectedly vanish and soon find themselves on a strange planet called Triskelion, where other alien life forms from across the galaxy, like themselves have been abducted and enslaved and trained as gladiators, where they have to fight for the amusement of the bored, mysterious and unseen Providers. Meanwhile, Spock assumes command of the Enterprise and begins investigating their mysterious disappearence and begins searching for Captain Kirk and the missing officers, much to the protest of Dr. McCoy and Scotty, whom assume that they are on Gamma 2.