On his own, PJ Robot decides to use the Tractotem against the Mecanolab to stop Roméo but he causes serious damage to the latter, which threatens to crash in the city. PJ Robot and Roméo must work together to stop it.
The following characters appeared in the episode "PJ Robot Vs Romeo":
The episode begins as Howler and Rip run down the mountain from an incoming boulder at Mystery Mountain. PJ Robot warns the PJ Masks about the ongoing situation, until the PJ Picture Player alerts him of another threat. Romeo’s Sky Factory is outside headquarters, firing some of the bouncy balls at the structure. PJ Robot retaliates by shooting furballs at the factory, but when Romeo fires another ball, it heads straight towards Catboy’s HQ room, bouncing around and damaging the PJ Picture Player.
Angered by this, plus Romeo’s mocking, PJ Robot summons the PJ Seeker and uses its robotic arm to fire one of Romeo’s projectiles that are spread around the moat. Romeo shoots another projectile, and it damages the vehicle’s mechanism. The PJ Masks return just as PJ Robot becomes increasingly frustrated. Noticing Romeo continuing to fire more projectiles, Owlette blows the balls away, one hitting one of the factory’s mechanisms. Romeo and Robot retreat for the night as a result, but PJ Robot is still angry.
The next day, the kids arrive at the soccer field to see one of Romeo’s bouncy balls wedged in the soccer goal. As Cameron angrily attempts to remove the projectile while the other kids are watching, Connor, Amaya, and Greg discuss how Romeo is making everyone mad, especially PJ Robot, who is madder than usual. The reason why is that the villain acts as if he still owns him. To make the robot feel a bit better, they decide to help him fix the PJ Seeker tonight.
Nighttime arrives, and the PJ Masks head over to HQ to meet up with PJ Robot, only to find him and the PJ Seeker gone. He is over at the park, throwing the leftover balls at the Sky Factory with the PJ Seeker’s repaired mechanical arm, still intent on beating Romeo, who then retaliates afterwards. The PJ Masks soon catch up with him. Seeing what is going on, they tell PJ Robot to stop and calm down, informing him that heroes fix trouble, not make them.
PJ Robot starts to comply, but when another ball damages the vehicle’s mechanical arm again, he gets more frustrated. The team warns him to stand down, reasoning that his attitude is negatively affecting Romeo, the town, and himself, and will worsen the situation, but it falls on deaf ears as he states that Romeo started the fight. He enters the PJ Seeker and drives away from the group. He charges towards the Sky Factory, but much to his dismay, Romeo activates his vacuum to take him back into his ownership.
Still inside the PJ Seeker, PJ Robot tries to find a way to escape the Flying Factory, but to no avail. Robot arrives to calm him down, while Romeo prepares to give him heavy amounts of work to do. Not willing to work for the villain again, he fires a laser at one of the projectiles inside the room. It bounces everywhere, and it destroys the machinery keeping the factory stable. PJ Robot then exits the vehicle and looks at the damage. He tries to reason that fair is fair, but after looking at the extent of the damage, which Romeo is not sure even he could fix, he begins to feel ashamed.
Meanwhile, the PJ Masks fly up to the Sky Factory in the Owl-Glider in an attempt to rescue PJ Robot. When they see it malfunctioning and falling apart, they realize it is going to crash and contact him about the situation. PJ Robot asks them to help, but with the malfunctioning gadgets and the falling pieces, they are prevented from boarding the factory. This means that PJ Robot and Romeo will have to work together to fix it. The two instantly refuse, but the team reminds PJ Robot of his desire to save the day, while Robot shares that Romeo is uncertain of fixing the Sky Factory on his own.
With this in mind, Robot gathers them together for a therapy session to discuss their feelings. PJ Robot is upset that Romeo can’t accept the fact that he is his own robot, while Romeo is upset about PJ Robot choosing the PJ Masks over him, even though he created him to do what he says. In addition, the Flying Factory is in danger of being destroyed. Since they are both upset, and keeping into mind of the situation, they decide to put their differences aside and finally agree to work together to save the factory.
The PJ Masks move around the town to catch the falling factory pieces. At the same time, a montage plays out as PJ Robot and Romeo fix the damage together, sharing a few praises with each other along the way. Soon enough, the factory is fixed, and it is working better than before. Romeo comments how PJ Robot had taken after him, but he still calls him what he used to be. PJ Robot just takes it in strides, though, and smiles.
Romeo releases PJ Robot in the town as the PJ Masks finish gathering up all the pieces, but only for now, because he secretly plans to take him back, now aware of what he is capable of. He then collects the pile before he leaves, stating to the team that he is going to use them to make his factory even stronger. PJ Robot apologizes for his behavior, and the PJ Masks commend him on the rescue, stating that he was able to fix it in the end, and that’s what matters. The PJ Masks shout out their signature victory phrase, and the episode ends.
With it, he uses it to talk to PJ Robot as they battle with each other at the beginning of the episode and to tell the PJ Masks that he is just collecting the fallen pieces to make his factory even stronger at the end of the episode.
Catboy (in the Owl-Glider), Owlette and Gekko didn't assist PJ Robot for the first time, as they were too busy collecting falling junk from the factory while PJ Robot and Romeo worked together to fix it.
Despite this, they (the PJs) still use their usual catchphrase instead of saying "PJ Masks, all shout 'hooray'! 'Cause in the night, PJ Robot saved the day!" like they did in "Big Sister Motsuki".
Also, PJ Robot saves the day by himself (with a bit of help from a villain) for the second time, the first being in the aforementioned episode.
Romeo narrates an episode title for the fourth time.