Intro: Raphael narrates as we see him racing a high-octane Planet Racer bike through an alien rain forest landscape. Right behind him is a group of menacing aliens riding flying Manta-Beasts.
Act 1: Open in the Turtle Lair. Raph and Casey are are working on their motorcycles, tweaking them for racing performance. Suddenly, Ultimate Drako appears with the Time Scepter. The TMNT leap into action, but Drako raises his staff and uses its powers to freeze our heroes in a flash of light.
Fade in from the blinding light as we see Raph falling from the sky and landing on an alien planet. Raphael stands and calls out to his family in bewilderment when a group of Planet Racer bikes plummet down from the mountains behind him - heading straight at the confused ninja! Bike #23 successfully dodges Raph, but they crash in the effort. Raphael is at first angry, but when he sees that the two riders are injured, he does his best to help them. Behind them, a group of hungry four-legged alien beasts are charging. Raph tosses the unconscious racers onto the back of the vehicle, and frantically tries to start it - but the beasts are catching up!
Act 2: Just as the monstrous creatures are about to pounce on the bike, Raph gets it started. The Turtle rockets the vehicle forward and escapes the beasts via some tricky riding, and bike #23 finally makes it to the finish of the race - in last place.
Later, Raph is at the medical infirmary with the riders, Godman Falcon, the pilot, and Methania Fitts, the team navigator. Methania has a serious leg injury and can't continue the race. The race commissioner, Tangent Morrey, calls Godman on a video comm and informs he that he's being removed from the race. Falcon is angry and argues his case, so the commissioner asks him who will replace Methania. Godman volunteers Raph to pilot the bike and states that he'll take over the navigation position. Raphael isn't happy with this and argues that he has to get home and help his family. Falcon states that Raph owes them for wrecking their bike in the first place - Methania speaks up and tells Raphael that her uncle is an expert in temporal science and she'll ask him to help the ninja - once he's finished the race series on the planet Laotora 4. Seeing no alternative, Raphael agrees to pilot Team Fitts' bike #23 for the remainder of the charity race.
Cut to Laotora the next morning. Raph and Falcon prepare to start as Team Koyoshada's bike #6, piloted by Tripper Nitro, pulls up beside them. Nitro mocks Godman for his performance yesterday. Falcon advises Raphael to watch out for Tripper as he doesn't play fair. Finally the green light flashes and the teams begin the next leg of the race, zooming through icy, subterranean "worm" tunnels.
Onboard the Stadium Ship where fans view the race, Planet Racer announcer Nobby Bloe questions Commissioner Morrey about the "worms" in the tunnels. Morrey states that he doesn't know much about them, but a little danger will be good for ratings.
As Team Fitts speeds by other racers, they come up to a three-tunnel intersection. Godman orders Raph to take the middle tunnel, but as they near the entrance, a giant worm with a mouthful of fangs pops out and attacks!
Act 3: Raphael makes a sharp turn for the left tunnel with the giant worm in hot pursuit. Suddenly, bike #6 zooms up from behind them and crashes into their racer - both vehicles crash to the ground. Team Fitts' bike can't gain its wheels as its stabilizers were damaged in the collision. Nitro activates his stabilizers and takes off as the worm closes in - ignoring Raph's call for help. Quickly thinking, Raph jams his sais into the ice floor, creating a fault line that enables our heroes to break through just as the worm arrives. As they fall, bike #23 lands on its wheels and Team Fitts is off again. Suddenly, Raphael begins to phase shift back to his own dimension, unable to control the bike! Fortunately it doesn't last long and Raph regains control.
Meanwhile, Methania has regained her feet and goes to question Commissioner Morrey about the lethal race course he's chosen. Tangent tells Methania to mind her own business - and to remember that he has the power to throw her out of the Planet Racers league.
Back inside the ice tunnel, Godman tells Raph to floor it as they're coming up to a jump. Raphael guns the throttle as the bike jettisons out of the mountain tunnel - revealing a miles-deep cavern beneath the racers. The worm follows, but plummets into the pit as Raph successfully lands on the other side of the ravine, back in the race.
Methania seeks the assistance of Planet Racer announcer Nobby Bloe, who has his own suspicions about the league Commissioner. Methania asks Nobby to help her expose Morrey and his cavalier method to gain ratings by endangering racers lives.
Outside, just as Team Fitts is back on track, Raph begins to phase from the reality again - completely unable to pilot the bike. With no one steering, the racer begins to shoot into the misty emptiness as it plummets over a ravine.
Act 4: As the racer falls off the path, Raph regains solidity and grabs the controls. Using a jagged ice outcropping as a ramp, Raph jumps the racer back on course and over the other racers. As they cross the finish line, Team Fitts is in first place!
Godman and Raph take the bike to Team Fitts' mechanic, Muk, who notes that it will take some time to fix everything.
The next day, the final leg of the race is to be run through an alien rain forest inhabitted by a race of tribal cannibals known as the Mud Riders. According to Commissioner Morrey, the Planet Racers have permission to ride through the Mud Riders territory, but as the bikes race along through a swampy area, a group of Mud-Riders on flying Manta-Beasts come out from hiding and swoop in to attack!
Inside the Stadium Ship, Methania approaches the Commissioner with a Race-Cam in tow. As Methania begins to speak, Nobby Bloe turns on her camera and broadcasts the following to the galaxy: the navigator asks the Commissioner why the Mud Riders have attacked. Morrey claims he has no idea, they had signed a treaty. Fitts then reveals that the treaty Tangent sent to the Mud Riders was rejected, not signed - and she presents him with a scroll from the tribesmen that states they will attack if anyone trespasses on their swamps. Morrey is unaware that the Race-Cam is present, and sneers that it's good for ratings if some racers get hurt or killed. After making this statement, the Commissioner notices the camera and tries to cover his tracks - but the damage has been done.
Cut back to the racers, as Raphael and Falcon are right behind Tripper Nitro. A group of Mud-Riders has set a trap that causes Nitro to crash. The angered natives close in on Tripper, spears in hand. Feeling honor-bound, Raph stops his vehicle to help the fallen riders, despite Godman's complaints that Tripper didn't help them in the ice tunnel. The ninja quickly defeats the Mud-Riders, and both teams are off again - Team Koyoshada in the lead. Falcon complains that Raph lost the lead due to his goody-goody attitude, and Raph growls that winning without honor is not winning (and then slaps his forehead, noting that he sounds like Leo).
Raph and Falcon close in on Nitro and take the lead just in time to win the race! As they coast to a stop, Raph begins to phase out again. Godman tells Raph that if he does nothing else, he can take pride in having been a Planet Racer. Raph smiles and places his ghostly hand on his partner's shoulder, telling him to "Race with honor." With that, Raphael disappears for good - but where exactly is he going?
Godman turns to face the Stadium Ship, repeating Raph's message, "Race with honor" as he waves to the cheering crowd.