During a routine transport to planet Gamma II, Captain Kirk, Lieutenant Uhura and Ensign Chekov are intercepted and abducted by a powerful and distant transporter beam. Arriving flat on their backs on a planet called Triskelion in the M-24 Alpha star system, they are immediately attacked by beings from several different species. Kirk and his crewmates have been brought to this planet to fight as gladiators in combat games in order to entertain and provide exciting gambling for the disembodied entities called the "Providers."

Joseph Ruskin (Galt)
Angelique Pettyjohn (Shahna)
Nichelle Nichols (Lt. Uhura)
James Doohan (Lt. Cmdr. Montgomery Scott)
Steve Sandor (Lars)
Walter Koenig (Ensign Pavel Chekov)
Jane Ross (Tamoon)
Victoria George (Ensign Jana Haines)
Dick Crockett (Andorian Thrall)
Mickey Morton (Kloog)