Darius and K9 go undercover to expose a criminal using illegal robot technology in what he calls "destruct-entertainment". K9 becomes a gladiator and has to face the evil Pain-Maker in a battle to the death. What is the sinister plan instigated by Thorne? K9 also befriends the other Robot Gladiators he sees as cybernetic ancestors, basic androids who have a heart and spirit that touches K9's superior consciousness.