Episode Title:Once Upon a Hero.Episode Description:Dirty Rat obtains Ace and Lord Fear's pieces of the Amulet in an attempt to summon his own minion, leading to the arrival of the cyborg Random Virus, Ace's old friend, who suffers from two conflicting programs. Mark is terrified of Random, but plucks up the courage to confront him when Dirty Rat commandeers Chuck's experimental robot to use as a secondary weapon. Ace comes to aid him, Lord Fear also arriving when Duff informs him of the rat's schemes. Mark rescues Chuck's robot and returns it to him so he can win a science competition, while Ace promises to keep an eye on Random, who lives in the town's junkyard.