King of the Hill (Part 1) is the first episode of Season 3 and the fortieth-sixth overall of Transformers: Robots in Disguise.
When the Autobots detect a new Decepticon, Bumblebee is confident they can handle anything and dispatches Strongarm and Sideswipe, only for the pair to find they've bitten off more than they can chew.
A highway patrol car pursues a grey SUV into Grand Valley, however the SUV manages to somehow get behind the car and ram it, sending it spinning out. As the SUV announces that the area is his turf, the two highway patrolmen in the car decide to organize an evacuation of the area, since there's a danger posed by a nearby nuclear waste disposal site.
In the scrapyard, Drift is practicing with his sword, Grimlock is playing tic-tac-toe with himself, and Sideswipe and Strongarm are sparing lacklusterly. Sideswipe is disgruntled at the lack of action they've had of late and complains to Bumblebee, who is cataloging Cybertronian artifacts. Bumblebee blows off the idea that they're going to get out of shape, though he's cut short by Grimlock knocking a bunch of shelves over on him. Russell is meanwhile practicing his football kicks while Jetstorm and Slipstream attempt to distract him. Russell's perfected his kick and is confident for the upcoming championship game. Fixit calls an alert — based on highway patrol reports, he suspects there's a Decepticon at large but is unable to get a signal due to interference in the area. Bumblebee orders Strongarm and Sideswipe to go check it out. The pair arrive in Grand Valley, where they find their comms are subject to the same interference that's messing up Fixit's instruments. Adopting desert camo, they begin patrolling the desert while bickering, and briefly encounter an alien-hunting hermit living in an RV.
Russell's championship game is ready to begin and he boasts to the other team that he's ready for anything, only for the other team to reveal they have an extremely tall kid on their side.
Sideswipe and Strongarm finally run into the Decepticon, Heatseeker, who informs them he's claimed the area for his chief. The Autobots give chase and attempt to pin the Con in a tunnel, however he gets the drop on them and brings the tunnel down. The pair only just get out before it completely collapses. They resume bickering, unaware that they're being observed by a mysterious Mini-Con, before returning to the pursuit. Strongarm contacts Fixit who identifies the Decepticon as a Stunticon and informs Bumblebee. Sideswipe tells Bumblebee he and Strongarm have it covered. Though Strongarm objects to this assessment, Sideswipe insists they can capture the Con, and the pair break out portable detectors to try and locate Heatseeker that way. They head to the top of a butte and survey the terrain, but a short time later two missiles are streaking towards them. The pair transform and attempt to evade the missiles, only to discover they're guided.
After Strongarm fails to shake her missile by driving through a ravine, Sideswipe comes up with the idea of an impromptu game of chicken. The two Autobots are able to swerve at the last moment, but the missiles have a slightly slower reaction time and explode, knocking the pair flat but leaving them functional. Strongarm attempts to contact the scrapyard for reinforcements.
Russell's game is coming up on half time, and Hank suggests he kicks a goal so they can get the lead. Unfortunately the extremely tall kid manages to block the goal and the game hits half time with Russell's team two points down.
Bumblebee has just finished indexing the first batch of relics when Strongarm's message comes in. Though Bumblebee's unconvinced the situation is likely to be as dire as Strongarm is making out, he, Drift and Grimlock step through the GroundBridge to find Strongarm and Sideswipe taking cover. After the pair explain the situation, Sideswipe points out the waste disposal site, and they realize a potential disaster is in the making. Bumblebee still thinks they have the advantage of surprise, until Grimlock points out the five missiles that are right now streaking towards them....
"Over there! Megatronus is forcibly removing sugared treats from the grasp of that human infant!"
- —Slipstream trying to distract Russell.
"Loud, obnoxious and ugly. Definitely a Decepticon."
- —Sideswipe gives his professional assessment of Heatseeker.
"Does the procedure manual cover this?"
"Yeah! It says drive faster than the missiles!"
- —Sideswipe and Strongarm realise they might be in trouble.