Ben was polishing Kevin's Car since he spilled a smoothy on it but then Gwen said that there was an urgent mission Max needed to send them on. They went to a Plumber Headquarters where Grandpa was sitting back and enjoying a worm sandwich. He said that there was an alien spy transmitter in the Blackrock Mountains that needed to be destroyed. Then a voice came from the doorway and there were Manny Armstrong, Helen Wheels, and Pierce standing at the door. They were saying that if they didn't want the mission they would take it. Kevin said they had dealt with a lot worse than some mysterious mountains and then Max said that he didn't care who destroyed the transmitter. (It was cloaked.) Then Kevin raced Manny down the hall to the equipment room, however, Helen grabbed it first. The three Plumbers-in-training got in there truck and drove away. Then Kevin got in his car and quickly followed. While on the road Kevin's tire popped and the Plumbers-in-training got away.Ben said that they fix it and he transformed into Jetray to keep an eye on them. Gwen and Kevin met Ben at a dinner but Helen came and grabbed their map. Kevin said they had gone too far and then turned to steel to fight Manny. He tackled him but then Gwen put them in energy bubbles and floated them away from each other. Then Helen gave the map back. But Ben said they keep it and said they meet at the trail head at seven. He shook hands with Pierce then. When they got there, they observed tire tracks and knew they started without them. Then they drove up. Then Gwen sensed big energy and they saw a big battle with a giant alien slug and the Plumbers-in-training. Then Ben turned into Humungousaur and lifted the slug up, but then it shot toxic green slime at Humungousaur. Then it shot it at the group but Gwen put an energy shield up. Then it was about to attack again when it started slithering towards Kevin's car. Gwen said that it must've thought his car was his friend since they were the same color. Then Kevin drove away and the slug followed as a distraction to find the transmitter. Then Helen uncloaked it and Humungousaur stomped on it. Meanwhile, the slug was giving Kevin's car a hug and then Manny shot his lasers at rocks above it, trapping it. Then at the Plumbers HQ, Grandpa Max congratulated them.