The Tennysons seem to be at a music festival in Chicago. Ben and Gwen seems to be a little freaked out about their grandfather Max’s current appeal. He tells them to get moving before they get late for a special event. Ben doesn’t seem to be excited much about the festival, and a weather man named Vance Vetteroy seems to catch his attention. Vance Vetteroy, and he appears to have just finished to announce the current conditions of the city of Chicago. Ben and Gwen seem to be excited about Mr. Vetteroy and his robot partner, S.A.M. Vetteroy did not seem to be happy much about them talking about his current affairs with the news station.
Vetteroy opens up a panel on the robot, and it asks him what he is up to. He tells him that he wants to try and attempt to collect a few cumulus clouds to produce some rain in the city. Vetteroy wants to “make the weather,” instead of reporting it. He launches the robot’s mind to the sky, and as it spins, it releases a chemical to quickly condense the airborne water in the sky into clouds. Unfortunately, a thunder hits S.A.M., and it causes it to react and malfunction. While Ben complains about how his day is turning out, a giant water monster appears on the top of the stage.
The monster attacks, and Ben is angered that his music player is busted. Vetteroy starts to make a news report about the water spout, having a mind of its own. Gwen and Grandpa Max take a look at the giant monster. Ben tries to transform into XLR8, although it malfunctions and changes into Heatblast instead. Gwen has an idea to stop the giant water monster. She tells Heatblast to rotate around it and gather enough heat to become a supernova temperature, causing it to evaporate into steam. Heatblast does what Gwen suggested, and it successfully evaporates the strange monster.
Heatblast transforms back into Ben, and he is glad that the problem is over for now, and he suggests that they go to the sumo slammer convention in Milwaukee. Grandpa Max seems to be none to happy about going to the convention. Grandpa Max makes a point that they have gone to places that Ben wanted to go to. Ben tries to attack by telling him visiting Aunt Vera was not his idea. Gwen tells him he still ended up having fun in the first place. Grandpa Max tells him that he wants to see his favorite old band, Shag Carpeting, although Ben does not seem to enjoy being around Chicago even more. Grandpa Max and Ben both turn to Gwen to explain whose point seems to be more acceptable.
In the news van, Vance decides to start tearing his partner apart. S.A.M. tells him what would his point be for doing such a thing in the first place. It tells him that he can be well known. At the festival, Max notices the booth for Shag Carpeting. He tells the kids if they would like to come along with him to get their autograph. Ben did not seem to care much about what his grandfather wants at the moment.
Vance tweaks up S.A.M. again, and launches him. Gwen finds it that it seems unusual to release a strange black smoke. Ben walks around to find something to do. He transforms to XLR8, and he is mistaken as one of the band members. He is brought into stage as the drummer, though he did not seem to do too well. Meanwhile, at the sky, S.A.M. releases strange static electricity to the people below him.
The strange smoke cloud travels throughout the city, and Vance attempts to try and take control of the robot. Luckily XLR8 was able to help people in time. XLR8 tries to catch up with the smoke monster, while Grandpa Max follows with the Rust Bucket. XLR8 decides to jump into the cloud, though he was shocked with volts of electricity, temporarily nullifying his body functions. He falls into the RV’s window. Vance tries as hard as possible to catch up with S.A.M. also.
XLR8 tries to catch up with the cloud again, so this time, he was able to get into the cloud and avoid the impacts. XLR8 spins himself to create a current, causing the robot to fling off the cloud and fall into a truck full of cement. XLR8 transforms back to Ben and falls into a nearby lake.
In the RV, Grandpa Max seemed to be disappointed that he missed the tour with Shag Carpeting, but fortunately he is given another chance when an announcement comes up that they are willing to continue the tour. Vance on the other hand, readies to smash his robot to bits, although it was powerful enough to take over and shield itself.
At the Shag Carpeting concert, they encounter the robot once again, but this time, a hybrid of water and cement, and literally affecting the weather at the same time. It is after the Tennysons, who successfully thwarted its plans twice in a row to take over the city. Ben transforms to Fourarms, and he tries to find a way to destroy the monster. Grandpa Max has a plan to actually shut down the robot. By creating a reverse feedback, it may be able to affect the robot’s function, causing it to malfunction and shut down. Fourarms climbs up the giant monster with two guitars, and opens up the skull the monster. He starts playing, causing S.A.M. to slur and function improperly. Fourarms transforms back to Ben, and he is knocked down by the monster.
Ben finds another way to get back up and continue to play, and this time, it finally malfunctions and shuts down, and the monster collapses. Ben slides down the monster and Grandpa Max catches him in his arms. They find the festival a mess, but they are glad that it is finally over.
The Tennysons enjoy the concert, and Grandpa Max tells Ben if he wants to go to the convention. Ben seems to have become more polite towards his grandpa, and tells him that they can go later instead.