Ben is tasked with cleaning the Rustbucket. But when he is tricked into letting the villainous and vile Fly Guys steal it, he must chase them down before they create an unstoppable Magg-O-Net Monster with sights firmly set on destroying Las Vegas.
The episode opens up with Maurice and Sydney in a desert robbing a cargo truck of all its toxic waste stored inside, they appear to be using it to fill up some machine. The machine is almost full, but they don't have enough waste, but then the find a vehicle that can be useful to them.
Later on, Max, and Gwen, are cleaning the Rustbucket, while most of the dirtiness is caused by Ben. While they are cleaning Ben (as Grey Matter) is watching cartoons on his tablet, Gwen tries to convince him to help them, but Ben decides to continue watching his programs. Max then give Ben his chore list, which is packed with things to do, so Max decides to leave Ben behind and do his chores while he and Gwen go explore so bat-guano caves, though Ben isn't too upset, knowing he can turn into a super fast alien XLR8, that get all of his chores done quickly.
Next, Maurice and Sydney are seen spying on the Rustbucket, they plan to take it to continue on with their plan. After Max and Gwen leaves, Ben turns into XLR8 in order to get his chores done. XLR8 later steps out to clean the bumper on the Rustbucket, he encounters the Bug brothers. XLR8 then figures out that Maurice and Sydney once swapped heads. Right after that Sydney punches XLR8 and both he and Maurice hijack the vehicle. Leaving XLR8 behind only to try and take it back, who then fails, soon after that he creates a Cyclone that only benefits the Bug Brothers. Ben later turns into Four Arms, who tries to defeats the bug brothers, his idea was to throw a huge bolder at them, but they stop right before it almost hits them, to relies that they were heading in the wrong direction. Then, Ben as Cannonbolt, attempts to knock them off course, but then failed and crashes into rocks. Ben tries to turn into another alien, but Omnitrix, is timed out, leaving Ben no choice but to continue on foot.
After what seems like hours of walking, Ben arrives at a toxic waste dump, later to find the Rustbucket clean as ever. Ben finds the Bug Brothers doing something, that seems to be no good, so Ben activates his watch and transforms into Four Arms, and starts to fight them.
After the fight, Maurice activates the magnet, creating a monster made out of maggots. Four Arms starts throwing things at it in order to take it out, Maurice then drops the remote that controls the remote, then Four Arms picks it up and destroys it, leaving the monster out of control. Maurice and Sydney runs away after the remote was destroyed, leaving Four Arms on his own. He later figures out that if he gets rid of the magnet within the Monster, he looks around finding something to throw at it, then realizes that he has to sacrifice a clean Rustbucket to stop the monster. He then throws it at the magnet destroying the monster.
After the battle Ben cleans up the Rustbucket himself without using his alien powers before Max and Gwen arrive, he asks Max if he can use Wi-Fi again, but Max reveals that he has way more chores left.
Ben encounters the Bugg Brothers for the first time.
Four Arms: So, let me get this straight. You stole our RV... so you can fuel that trash machine... to power a magnet that attracts maggots... to make a monster... that would eat Las Vegas? Whatever! TIME TO THROW STUFF.