The Secret Invaders (Part 2)
Speed is recuperating in a room at the National Hospital. The President is also in the hospital in room 1. Of course, Speed is in room 5. Rudolph Elegantor is there to pay his compliments on behalf of Vice President Duper, who looks a little like Hitler without a mustache. Speed is invited to the Vice President's home. Racer X also pays a visit, but when he hears of the invitation to Duper's home, he changes. Could he be a secret agent? Speed visits the Vice President, who lives underground. Speed is locked in a room to wait for the Vice President. Speed is escorted to see the Vice President, but on the way, a gun is pulled on him. Speed wrestles the gun away, but his advantage is short-lived. He gets hit over the head. The Mach Five leaves with someone disguised as Speed. Racer X arrives at Duper's home and is told Speed left. He takes off in search of his long-lost brother. Meanwhile, Speed is really in the trunk of the Mach Five, still unconscious. He's put in the car and the Mach F
Aired 26/01/1968EP 39 - The Secret Invaders (Part 2)

Speed Racer
The Mach 5 is one of the fastest and most technologically advanced race cars built by man. Equipped with various gadgets and a powerful engine, it provides a challenge for anyone who would dare race against it. The driver of this amazing vehicle is Gou Mifune, a teenager who dreams of breaking into the world of professional racing.
In spite of this, Gou's father and the creator of the Mach 5, Daisuke Mifune, does not want his son anywhere near a racetrack. Undeterred, his girlfriend Michi, younger brother Kurio, and Kurio's monkey sidekick Sanpei become Gou's biggest fans as he sets out to become the greatest racer of all time.
However, Gou soon learns that becoming a professional racer is not easy. From the underhanded plots of corrupt businessmen to stiff competition in the form of his rival, Racer X, Gou faces many obstacles on the road ahead, and has a lot to prove before he can cross the finish line.
(Source: MAL Rewrite)