Summary by Steve O'Hearn.
First of all, here are the characters:
Speed
Racer X
The Car Acrobatic Team - consisting of a leader who looks like a skeleton, but who's name is not mentioned in this episode (I watched it twice, and couldn't get it), and I would guess about two dozen or more expert acrobatic drivers, who perform shows, drive in formation, perform stunts, etc. - and have a vendetta against Speed. (This same team raced in the Alpine race).
Mr. Supremo - leader of the International Spies, Incorporated
Mr. Magneto - works for the International Spies, Incorporated
The Agent from Hong Kong - works for the International Spies, Incorporated
Trixie
Spritle
Chim-Chim
Sparky
On to the episode:
THE TRICK RACE
This episode is one of the more dramatic of Speed's shows. It's one year after the Alpine Race. The Car Acrobatics team meets under a stormy, brooding sky, flaming torches in hand, and declares that they will have their revenge upon Speed Racer. Their leader recalls how members of their team died during the Alpine race, and how Speed defeated them. As the thunder claps and the lightening strikes, the team leader declares that the "we will not only defeat him, we will destroy him."
Meanwhile, Speed is tortured by nightmares from the Alpine race, the haunting memories of the icy caves, the treacherous cliffs, the dangerous storms, the mountain top roads that were destroyed by the torturous weather - how the surviving racers had to jump over deep, yawning chasms, on the brink of disaster, how many had died there, how he almost died.
He wakes up, grasping a letter in his hand. "So the Car Acrobatic team challenges me to a race. OK!" - and he runs out the door, into the stormy night.
On his way, Speed has second thoughts. He recalls the uncanny skill of the Car Acrobats, and the more he remembers, the more worried he becomes. Before he arrives at the race, Racer X intercepts him. Somehow Racer X knows what's going on, and Speed asks how he knows - but Racer X won't say. "A race is not a fight", he warns - and tells Speed not to race the Car Acrobatic team. But Speed won't listen, and races off to meet his challengers, more determined than ever.
At home, Pop is suffering from a fever. Trixie tries to comfort him, but all Pop can think about is his long lost son, Rex. He remembers the day that Rex ran away - the afternoon race, Rex's terrible crash, how Pop ran out to see if Rex was all right - then, discovering he was fine, scolded him for racing at such a young age. Pop forbade Rex to race any more, and Rex couldn't accept it - and ran away from Pop, running away from the fiery crash, away from the track - never to be seen again. Pop calls out to him to say that he's only wanting him to wait and race after he grows up - but it is too late. Rex was gone.
Meanwhile, at a meeting of International Spies Incorporated, Mr. Supremo enters a high-tech crowded board room. Mr. Supremo asks Mr. Magneto for the report. The subject is their enemy - the international secret agent Racer X. They review films of Racer X in action, foiling plans of the International Spies, Incorporated. "This secret film was filmed secretly", announces Mr. Magneto, as Racer X is shown deftly handling automatic weapons, cleverly escaping the most dangerous situations, and saving others in the process - including Speed and Trixie. The Agent from Hong Kong helps to narrate some of the secret film, showing how time and again, Racer X has stopped their plans. Mr. Supremo asks what is being done to stop Racer X. Mr. Magneto describes the efforts, and acknowledges that there is another problem - and the film shows Speed Racer in action. Mr. Supremo asks who Speed is. "A professional racer - one of the best", answers Mr. Magneto. Mr. Magneto adds that they have discovered something important - that Racer X is really Speed's brother, and that Speed himself doesn't know it. Furthermore, they know about the upcoming rematch between the Car Acrobatic team and Speed. They know that, under these circumstances, Racer X will be somewhere near by, looking out after his younger brother. The spies lock in their plan - to attack Racer X when he shows up for the race, and let the Car Acrobatic team "take care" of Speed.
Speed meets the Car Acrobatic team. They declare their intention to race again, a rematch of the Alpine race - but just the CA team and Speed. The team leader concludes his speech by referring to the letter that Speed had written them - and Speed wonders aloud, saying that he didn't write any letter, that he received one from them - but the moment is gone, and the Car Acrobats are ready to race. They begin ...
Meanwhile, Racer X races nearby, keeping on eye on Speed. But the spies are waiting for him, and confront him as soon as Racer X emerges from a cave. Racer X evades them, and through a series of confrontations and deft driving, manages to get away. He finds one spy, though, who Racer X disarms and interrogates. The spy confesses that the race was set up by the International Spies, Incorporated, and that there are time bombs in each of the Car Acrobatics team's cars. The spies were counting on the Car Acrobatics team surrounding Speed's car, so that the bombs would blow up everybody. Racer X speeds off to save Speed.
As he drives away, the spies catch up to him. Mr. Supremo takes careful aim with his high-powered rifle - and shoots Racer X in the back of the head. Racer X slumps back and veers off the road. The spies drive on, satisfied.
Meanwhile, the race is on, and Speed and the Car Acrobatics team are close together. Suddenly, on the road in front of them, Racer X's car drifts out, blocking the way. He slumps forward in his car. As the drivers recognize Racer X, they come to a stop at his car. The CA team leader sees that Racer X is hurt, and Speed leaps out of his car to run to him. But Racer X ignores his own pain, warning the others about the bomb, the letters, the spies, and how they were all set up to draw out Racer X for the spies to attack him. The Car Acrobatic team's leader sees a fellow racer in danger, and recognizes that they have all been targets of the spies. Everyone agrees to work together to defeat the spies, and race their rematch another day. Racer X warns them that the bombs are set to go off in about an hour.
The racers drive to the spies headquarters, and surround the building with the Car Acrobatics team's cars, then evacuating the cars in a panic. Within seconds the cars all explode, blowing the building of spies up into the sky.
A helicopter appears in the sky, carrying Trixie, Spritle and Chim-Chim, *** ANOTHER GUY I DON'T KNOW. SOME PIT CREW GUY ***. Before it lands, the team says good-bye, as does Racer X, and they all begin to walk off - but Speed calls out to Racer X. Racer X turns around and walks back to Speed.
"Are you my brother", he asks. "Are you my brother Rex Racer?".
Without hesitation, Racer X punches Speed in the stomach, knocking the wind out of him. Speed collapses on the ground, unconscious. The Car Acrobatics team leader announces - "You are his brother! I can see the resemblance, even under that mask". "Yes", says Racer X. "But even though I am his brother, I can't go home again."
Racer X announces that his racing days are over, and that he will become a full-time international secret agent, without a name or a country. But he will continue to keep an eye on Speed. He takes off his mask, revealing himself clearly, and throws his mask down next to Speed's head. Racer X and the Car Acrobatics team exit quickly.
Trixie, Spritle and Chim-Chim, and Sparky arrive. Speed wakes up, finding the mask, and calls out to Rex, convinced he's found his brother. Trixie asks him if he's finally found Rex, but Speed just runs to the edge of a nearby cliff, stopping to think about the events of the day. He vows out loud to be the best racer in the world, so that Rex will be proud of his younger brother.
END OF THE TRICK RACE