Former robot assassin Zeta meets teenage Ro, who is also on the run and having troiuble with a gang that wants her to shoplift. He helps her and then she distracts the NSA for 500 creds from Zeta's unlimited account. Ro gets tagged by the NSA as being Zeta's ""accomplice"" soshe stays with him. They set out to locate the scientist who originally created Zeta, in hope of proving to the government that Zeta is peaceful at heart and should not be destroyed.

Zeta goes after one of his creators but Bennett finds out about it and tries to capture him but his creator helps him escape and tells him the guy to clear his name - Selig, the head of the Zeta project.

Ro and Zee encounter Bucky, a brilliant but bratty kid genius, while looking for Dr. Sellig at at science competition. Bucky's supervisor Dr. Tannor steals his invention, a remote that can control any mechanical device. When he offers it up at the competition as his own creation, Bucky takes control of Zee and sets him after his Tannor for revenge.

Zee and Ro track Selig to a museum in Grandview, but get waylaid when a little girl becomes trapped in a fusion power chamber. Zee reveals himself and fights to save her life, while the NSA closes in.

Zee and Roe head down south to intercept a drug lord, unaware that the government has sent a new, improved model of the Zeta robot project on their trail. Bucky gets hold of the info as well, and goes to meet them. Zeta's efforts to stop the drug lord are complicated by the killer robot on his trail, which possesses all of his abilities and superior strength as well. At the end Zeta manages to seemingly destroy it, but as they head back to the States, the tracking robot begins to repair itself.

Zeta and Roe flee on a train to avoid pursuit, and only Agent West manages to get on the train with them. Their efforts to avoid him are complicated by the fact that as the monorail train passes through certain electrical barriers, Zeta's hologram projectors go out of control, forcing the robot to change into different people at random. Despite this, the pair manage to escape and save the train after West's shots endanger it.

Ro returns to visit her first foster family, the Morgans, in hopes of digging up information on her biological family. Determined to show them she wasn't a failure, she creates a rich girl persona via Zee's unlimited charge-card, but Zee goes overboard when he holograms as a famous vidstar. Things get dangerous when he's revealed as a robot, but before the pair escape Ro discovers evidence that she has a brother.

Infiltration Unit Seven returns, and a brutal battle errupts in a mall. Ro is hurt and taken to hospital, and Batman picks up on it from Bruce Wayne. Vid records make it look like Zee is solely responsible and Batman vows to take him down before he can hurt anybody. Meanwhile, Zee contemplates abandoning Ro so she will not be put at risk anymore. IU7, Zee, and Batman duke it out in an explosive hospital battle.

While enjoying a day on the beach, Zee and Roe intervene when a child is set upon by a local gang. The child, Wade, is actually a rich snob who mistreats his robots. He invites the duo to his home, and introduces them to his bodyguard Sven and his robot servants. When Wade is later kidnapped, Roe and Zee are implicated in the crime. They confront the gang they met earlier, who reveal they were hired by Sven. Going out to Wade's family's yacht, they find that Sven is holding him there for ransom. Zee and Roe manage to free the kid and beat Sven, and Wade has a new appreciation of robots.

Fleeing from Agents West and Lee, Zeta and Roe are lured to an abandoned candy factory by Knick, a bounty hunter. Knick plans to collect the reward by any means, using first Roe and then Lee as hostages to gain Zeta's surrender. Using the factory's automated ""Cody Koala"" robots, Zeta manages to rescue them. Agent West tries to shoot Zeta, but Lee ""accidentally"" stops him, as she begins to realize that Zeta is in fact acting of his own free will and out of concern for human beings.

Ro takes a chance and appears on a Jenny Jones/Oprah like show because they claim to be able to reunite her with her brother.

Zee and Roe are riding through the desert on a hoverbike when it is taken over by boy-genius Bucky and brought to his home. His parents are missing, and are working with Bucky's nemesis Dr. Tanner on some kind of youth-restoration project. Bucky wants the duo to help him. They go to Tanner's spa and discover that the youth-project has gone awry. Bucky's parents, and most of the customers, have become children, while other customers have become devolved apemen. Tanner' knocks out Zeta and forces Bucky to work for him to try and reverse the process. Bucky and Roe manage to escape, as does Zeta. An explosion triggers the nearby mud-geysers, destroying the complex. Zeta downloaded the schematics so they can restore Bucky's parents to his normal age, while an escaping Tanner is stuck with the rest of the ""children"".