At a nuclear missile control center, three pods are activated and opened up. Inside, a red alert has been set to indicate the launch of the missiles. A nearby officer immediately orders his operator to abort the launch, though he is unable to, as if something is pulling them out of their silos. As the nukes are pulled towards the sky, a ship floats nearby the area. Back inside the building, Vilgax enters, and his drones shoot the officers to make way. He looks around to see if he can take anything he can use. Someone then shoots down one of his drones, then directly at him. He blocks the weapon fire in success. Two men in blue suits armed with heavy weaponry, and they seem to be going after Vilgax. Vilgax identifies the one who shot him as Phil. Phil runs after him, but Vilgax jumps up and kicks his helmet off, revealing Phil’s true face. As Vilgax holds Phil as his captive, he threatens the other man in the suit by pointing his weapon at Phil. A nearby drone then activates another missile, and Vilgax tells them that it is headed directly to one of the cities in the Earth.

Vilgax orders the man in the suit to put his weapon down. He does, and this lets Phil think that he is lying about not letting him get away. He said that this is not the case, and he shoots a laser from his wrist that knocks the gun off of Vilgax’s hand. Phil then pushes him off of him. Vilgax thought that he succeeded his plan to destroy the city, but the man was able to shoot a material directly at Vilgax to send him along with it. The man removes his helmet, and Vilgax is angered by his tactics on stopping his plans. Tennyson is what Vilgax shouted at the top of his lungs before hitting the ship, and it may very well be that the man is none other than Max Tennyson, in the older days in what he used to do.

As Grandpa Max finishes telling his story of his mysterious past, he concludes that he thought to have destroyed Vilgax, until to this day. He says that he was an ordinary man, doing his job, though Gwen’s curiosity comes in to ask what specific job it was. Grandpa Max continues on, and he says that he used to work at a secret organization, referred to as The Plumbers, who were sworn to stop anything extraordinary, extraterrestrial, something that’s out of this world. Grandpa Max’s past continues to interest Ben more, excited that he has been with an ex-alien hunter. Gwen just seems that Ben is a little bit over his mind. As they pull over to let the authorities pass by, Ben’s excitement continues and he decides to transform into XLR8. The Omnitrix malfunctions again, and this time, he transforms into Ripjaws.

The firefighter asks what seems to be the problem, and the man claims that there seems to be some sort of creature inside the building. It starts to rain, though it was only Ripjaws holding up the hose to moisten his sensitive body. Ripjaws enters the building, and he calls out, hoping to get an answer. An alien appears and growls at Ripjaws, though it is shown that it is small in size, which makes Ripjaws cry out in laughter. This angers the little alien, and he throws a large rock, which knocks down Ripjaws. The alien then jumps into the fountain, and spits out water straight at Ripjaws. This only makes Ripjaws feel more comfortable. Outside, Gwen asks an officer if he saw any talking fishes around the premises. Meanwhile, Ripjaws continues his feud between the little alien, and Ripjaws bumps onto somebody with a large rifle. He says that he’ll deal with him later. He eventually gets topped over by shelving, though the alien too is caught afterwards. Ripjaws then transforms back into Ben.

Grandpa Max identifies the man as Phil, his old partner, back at the time when he was working with the Plumbers. Phil takes them to his car, and he says that he’s happy to see his old partner again. He said that the people should be grateful that he was there to stop the little creature. Ben immediately reacts to this, claim that he was the one who did. Grandpa Max stops Ben before he says anything further. As Phil offers Grandpa Max to join the Plumbers again, he says no thanks, and explains that he is already retired. Grandpa Max then gives his goodbye to Phil before Ben continues to gloat about his Omnitrix.

Inside the RV, Grandpa Max says that the Omnitrix should be hidden in secret, and the less people, the better. Ben would have realized this, but he continues on. He insists that Grandpa Max, Phil, and himself to re-establish the Plumber organization. Grandpa Max tells Ben to not re-live the past. Then suddenly, a monitor from the RV’s dashboard comes out, and the transmission appears to be from Phil. He reports that he needs help, and that there are Vulpamancers on the loose at the meat processing plant. The distress call makes Ben more excited.

They arrive at the plant, and they hear growling from within. They meet up with Phil inside, and they spot the beasts that are on the loose. Ben identifies them as “Wildmutts,” and he decides to transform into the alien, hoping to communicate with them. His plan immediately fails, as Grandpa Max explains that Vulpamancers don’t cooperate with others, even with their own kind. As Wildmutt runs away to avoid being attacked, he climbs on hanging chains that eventually lead him to a belt that leads meat to a grinder. The Vulpamancer was able to keep Wildmutt from moving, though Phil was able to save him before he entered the grinder. Before the gang was able to escape, they were surrounded by the beasts, and are trapped. Phil then takes out a device that emitted sonic waves that tame them. Phil asks Ben for forgiveness as it affects him too. Suddenly, one of the Vulpamancers was able to swipe the device off of his hands, and was about to take Phil down. Grandpa Max, however, was able to take them and pushed them to a room where they were eventually isolated by a door. Phil is happy to team with someone he knew for so long, and he asks for a new partnership together with Grandpa Max. Grandpa Max, however, seems to be bothered by it.

Inside Phil’s house, Ben digs in some shrimp. Grandpa Max looks around the house with suspicion, thinking how much money it would have cost. Phil then makes a deal with them, to try and establish the Plumbers again. As Grandpa Max thinks, he questions how three aliens in one day come to Earth all of a sudden. Grandpa Max’s suspicions lead him to go out and investigate more. Phil, however, also has been thinking that Grandpa Max may know something. Phil tells the kids that he’ll bring in some room service. On the other hand, Gwen wants to check out what is going on between them. Ben transforms to XLR8, and they head out to look for Phil and Grandpa Max.

At Mount Rushmore, Grandpa Max finds that a specific device is gone from where it belongs. Phil arrives behind him, who seems to be holding the device, called the Null Void Projector. Grandpa Max’s suspicions were correct, and Phil is using it to release the aliens they captured in the old days, and re-capture them for money. Phil admits for his conduct, and he’s not surprised that Grandpa Max would eventually find out about his plan. Phil decides to release another alien, this time large in size, and green in color, with a similar body appearance to that of the Vulpamancer.

Luckily, XLR8 arrives in time to save Grandpa Max from the alien’s attack, and he finds all about Phil’s plan. As Phil leaves them behind, XLR8 gets busy fighting with the green alien, while Grandpa Max looks for something he can use to tranquilize the beast. Grandpa Max eventually finds the device, only after Ben is knocked down by a large piece of the floor. They now set out to track down Phil, and Gwen is in his car, while Ben and Grandpa Max take the RV. He powers it up, and in a flash, they travel at high speeds with the help of rocket thrusters built in.

Meanwhile, Gwen spots the Null Void Projector, and tries to take it. Phil sees her and tries to take it back, not paying attention to the road. Up ahead, he was about to be hit by a truck, though he was able to dodge it. He then sets the car in auto-pilot, and he continues to try and take the device back. While they fight over it, they activate the device, and Phil sees the RV behind them. The beam releases a Null Guardian. Ben attempts to stop it by transforming to Four Arms, though it malfunctions and transforms him into Grey Matter instead. So he runs up the alien and grabs its projections on its back, which he uses to hold on and control it. He directs it to Phil’s car, which them leads it to the edge of the cliff. Again, Phil insists Ben to join him, though he continues to decline his offer. Phil decides to trap him inside the Null Void Projector. Luckily, Gwen sees him activating it, and it causes the beam to reflect back on him, causing himself to be trapped inside the device.

They use the device to trap the aliens Phil previously released. Grandpa Max then realizes that he should have told his grandkids about his job earlier. They don’t seem to be bothered by that much. As they leave behind the Null Void Projector and the Mount Rushmore hideout, the episode ends to reveal Phil’s fate for ever trying to start the Plumbers organization again in an evil way.