Adventure Bay is busy filming for a big action movie, with the main attraction being the giant, remote-controlled, animatronic robot. Everyone is taking part in the film, with Danny getting some upside-down shots for the director, Francois as the hero, and Marshall acting as the on-scene safety pup to ensure there are no fire threats from things such as the scripts being left under the heat of a spotlight or having too many appliances plugged into one socket.
However, Mayor Humdinger and the Catastrophe Crew show up, and upon learning of how Mayor Goodway's town is helping with the movie, Humdinger, jealous of Goodway getting all the glory with the movie they are filming, tries to figure out some way to move the film set to Foggy Bottom from Adventure Bay. Realizing that the robot is the key to his plans, Humdinger disguises himself as a postman to deliver a decoy package to the person in charge of the robot. While she is distracted signing the form for it, Cat Skye steals the remote. When the robot's handler discovers the trick, Humdinger is already in possession of the remote, but due to how complicated the controls are, he is unsure how to drive it, and as it stomps away, he takes off in pursuit on the Catastrophe Crew's kitty carrier. However, as he tries to work the controls, he causes the robot to launch a fireball that leaves an umbrella badly burnt, forcing Marshall to put it out with his water cannons before it can reignite.
With things getting way out of hand, Mayor Goodway pleads for Ryder and Marshall to stop the robot. Ryder assures her he's on it, and summons the pups to the Lookout for an Ultimate Rescue. Once they arrive, as the elevator ascends topside, the PAW Patrol shield changes to appear as Marshall's badge, and the pups are suited up in firefighter suits. Ryder appears sporting his own fire chief's uniform, and reveals their Ultimate Rescue to be one with Marshall as team leader. Skye is to provide overwatch and keep an eye out for the robot, while Marshall leads the rest of the pups from his Ultimate Fire Truck. With the orders given, Ryder heads down the fire pole, while Marshall heads down the slide. Like Chase and Skye, once in his partially-transformed pup house/fire truck, it is lowered into the maintenance area to be outfitted into its Ultimate Rescue appearance, which bears some similarities to the tiller ladder trucks used by several fire departments in real life, with a large reel line hose and controllable grapple claw fitted to the sides. Once completed, the Lookout rises to allow Marshall to drive his Ultimate Fire Truck out onto the driveway to pick up the rest of the pups, and joined by Ryder on his ATV, repainted in the black, yellow, and red of fire trucks, they speed off to the rescue.
Meanwhile, as Humdinger tries to pilot the robot through Adventure Bay with the remote control, still having much trouble working out which buttons do what, he is being pursued by Mayor Goodway and Danny in her personal car. At one point, he causes the robot to shoot another fire ball at the bell on top of City Hall, leaving it a smoldering red hot mess due to super-heating the metal the bell was forged from. He also causes the robot to bake a pair of pies that Mr. Porter was holding to perfection, much to Mr. Porter's surprise and satisfaction. However, when some fruit is sent flying, it leads to Chickaletta landing on the robot's head and being carried off by it, forcing Mayor Goodway and Danny to resume pursuit with Ryder and the Ultimate Fire Truck joining them. Skye takes to the air to keep an eye on the robot and relay its whereabouts to Ryder and the Ultimate Fire Truck.
As Humdinger continues to mess with the controls to the robot, he causes it to stomp on two parked cars, turning them into roller skates for the robot. It is not until it rolls into a large lot where a lot of crates and other junk is that Marshall is able to stop the robot by using the Ultimate Fire Truck to establish a large barricade that the robot can't roll through. With the robot stopped, Ryder confronts Humdinger, demanding the remote control back. However, during all the craziness, the robot's antenna that receives signals from the remote control is knocked off. Without it, the robot goes berserk. Humdinger hands the remote over to Ryder anyway, fed up with being unable to figure out the controls, but the robot launches another fire ball, charring some crates that Marshall quickly moves to put out, before Rocky spots the red-hot antenna and cools it off. Realizing that if they can get the robot to stop, Rocky can effect repairs, they soon learn it is heading for Farmer Yumi's.
At Yumi's, she is tending to the strawberries when the robot arrives, still using the cars as roller skates. The robot launches another fire ball, this time landing a direct hit into Yumi's silo where she had stored all her corn, causing the roof of the silo to pop off as the corn pops from all the pressure. Humdinger arrives to once again get control of the robot and drive it to Foggy Bottom, but ends up being carried off by it, much to the amusement of the Catastrophe Crew. Marshall has the pups help him cool off Yumi's silo, while he deploys his rescue cart to deal with the silo roof.
However, as they resume the search for the robot, Skye reports that it is heading straight for the Lookout, intending to make it the next target for its fire ball launcher. Ryder and the Ultimate Fire Truck arrive back there just in time, and once Rubble, under Marshall's instructions, helps Humdinger off the robot, as he ended up snagged on the tail as it continued its rampage, Marshall is finally able to rescue Chickaletta, but the robot soon turns around to focus its attention on the Ultimate Fire Truck, and prepares to fire. However, with Ryder, aided by Rubble and Zuma, using the reel line, Rocky and Chase the main monitor, and Skye adding a few water bombs of her own on a pass, they pump enough water into the robot's fire ball launcher to not only stop it from firing, but cause enough water damage to short out the robot, stopping it for good.
Mayor Goodway is relieved, and soon enough, when Danny mentions how this would have made a great movie, Ryder points out that he never turned off his helmet camera, so it recorded the whole thing. As a result, some time later, everyone gathers to watch the movie, but when Humdinger arrives to watch it, thinking he's the star, when Rubble arrives with popcorn from Yumi's, Humdinger is about to have himself a couple of handfuls before being scared off by the repaired robot, fearful of suffering another case of what happened earlier. As the director prepares to show the movie, she gives an extra special thanks to Marshall, who is the hero and star of the movie for what he accomplished as team leader for the Ultimate Rescue in his Ultimate Fire Truck, and everyone enjoys the movie.