Darius and K-9 go undercover to expose a criminal who us using illegal robot technology in what he calls ‘destruct-ertainment’. K-9 becomes a Gladiator and has to face the evil ‘pain-maker’ in a battle to the death. But what is the sinister secret plan instigated by Thorne? K-9 also befriends the other robot gladiators who he sees as cybernetic ancestors, basic androids who however have something of a heart and spirit that even touches K-9’s superior consciousness.