Blaze and Crusher discover a medieval kingdom with knight trucks, and they become knights themselves and participate in a royal race with them. But it'll take lots of skill for Sir Blaze help the knights get past obstacles and beat the always cheating Sir Crusher.
In a forest, Blaze and AJ appear out of nowhere as AJ greets the viewer. Crusher then shows up, thinking he's much faster than Blaze is. Blaze decides the two have a race to find out who's faster, and race for a while.
Pickle watches the race from aside, impressed by how fast they are, only to take sight of a warning sign reading "Watch out - road ends". The trucks were unable to notice in time, and end up falling down a cliff. Pickle joins them afterward.
At the bottom of the cliff, AJ spots a kingdom with a castle in the distance, and four royal knights appear from out of nowhere. The quartet go check out just as a heralding truck announces the knights one by one: the Purple Knight, the Green Knight, the Yellow Knight, and the White Knight. The knights go to a training ground to practice as Blaze, AJ, Crusher and Pickle watch.
After some practicing, the King appears to announce the start of the "Royal Race", where the knights have to race across the kingdom and the first to finish will win the Golden Sword Trophy. Crusher is determined to get the trophy, and Blaze decides they join the race and suit up in knight armor of their own, adapting the ailises of Sir Blaze and Sir Crusher, respectively. They join the other knights at the start, and the race begins as Blaze On is heard.
Blaze leads the knights to a nearby drawbridge, but it raises before any of them could even cross it. The knights realize this is cheating, and Blaze and AJ immediately find out Crusher was behind it. At the top of the drawbridge, Crusher reveals he locked the drawbridge and stole the key, only to lose control and drop it. Blaze catches it, but to get the key into the lock, he uses a bow to shoot it there. When Blaze pulls the bow, it stores potential energy - energy that's waiting to come out. With help from the viewer, he successfully gets the key in the lock and lowers the drawbridge.
The knights go on, practicing their potential energy skills all while Blaze and AJ sing Potential Energy in the background. Meanwhile, Crusher is far in the lead as Pickle cheers him on in the role of a court jester when he hears Blaze's horn and realizes they're on his trail. To stop them, he releases a bunch of barrels which trap the knights. Blaze manages to free them with help from the viewer, deciding which knight is in which barrel and breaking them with his shield.
Crusher is still in the lead, Pickle cheering him on, but then he hear Blaze coming and thinks of another way to cheat and stop him and the knights. He deploys a series of fiery robot dragons, which blow smoke to block Blaze and the knights from going on. Luckily, Blaze has some water balloons which will stop the dragons, and transforms into a catapult to launch them. He manages to find the dragons with the viewer's help, and extinguishes each one before going on.
AJ then sees Crusher nearing the finish line, and Blaze uses his Blazing Speed to catch up to him. Determining to find out who's fast once and for all, the two trucks race each other like they did at the start, only for Crusher to throw a mud ball to stop him. Blaze deflects the mud ball with his shield, making it hit Crusher instead, and wins the Royal Race.
The knights join and congratulate Blaze for winning, and the King presents him with the Golden Sword Trophy, followed by some cake for everyone as a celebration. As Crusher wallows that he lost, Pickle presents him with a slice of the cake which he goes for, but he loses control and it falls on him much to his disgust as Pickle eats it, ending the episode.