Two gorillas are racing on a course, and Urko and the local prefect are watching. The prefect points out that Urko sets the bet and demands the race, and laughs when the prefect points out that he has never laughed.
Along the course, one of Urko's gorillas snaps a branch into the prefect's rider. Urko's rider Kagan comes out ahead but the horse throws a shoe and the prefect's jockey wins. Urko's lieutenant Zandar tells him to make sure the horse is show for the next race in the village of Venta, and if it happens again then Urko will have Zandar killed as well as the blacksmith.
In Venta, Pete and Alan are helping the blacksmith, Martin. Meanwhile, Martin's son Gregor talks to Galen, and Galen admits that it was years before he actually spoke to a human. Zandar and his men ride up and Martin and Gregor go out to greet them. The gorilla tells Martin to take care of Urko's horse if he wants to keep on living. One soldiers points out that there are reports of a young human riding a horse, and says that the human will be killed if he's caught.
Once the soldiers leave, Martin angrily tells Gregor that he will eventually be caught no matter what he thinks. He demands his son's word that he won't ride again. Before Gregor can respond, Galen screams in pain as a tiger scorpion stings him. Martin says that without an antidote, the scorpion's sting is fatal. The only antidote is at the clinic five miles away, and Alan offers to ride one of the horses. Gregor warns that he'll be caught and offers to go, and the astronauts reluctantly agree. Once Gregor leaves, Martin says that the tiger scorpion never stings if the victim doesn't move.
Gregor takes a back route to the clinic, dismounts, and walks up to it. Once he gets there, he claims that his brother was bitten by a tiger scorpion. The doctor gets him the antidote and Gregor goes back to his horse. Zandar and his men make camp nearby, and Gregor has no choice but to ride past them. One of the soldiers thinks that it was Gregor, but didn't get a good look. The soldiers open fire and wound the horse.
Martin and the astronauts wait for Gregor as Galen dies. Gregor rides up and gives them the antidote, and Pete administers it to Galen. Meanwhile, Martin sees that the horse is wounded and realizes that they're in trouble. They take the horse into the barn to take out the bullet. Alan goes out and removes the bullet, just as the soldiers ride up. Martin orders Gregor to hide and Zandar sees the bullet wound. He assumes Alan rode the horse, but Gregor steps out and admits that he rode. They take Gregor away and beat Martin down when he tries to intervene. Zandar says that Martin will be invited to witness the execution at the celebration after the race and rides off.
Later, new Prefect Barlow receives a new saddle but admits that he has no chance of winning the race against Urko's jockey. Urko transferred Barlow there and set half of Barlow's horses and lands if he loses.
Alan and Pete tell Martin that they want to help by talking to the prefect. When Martin mentions Barlow's name, Galen joins them and says that Barlow is a friend. The astronauts try to persuade him not to go, and Galen borrows a horse from Martin and tells Alan and Pete to walk. They arrive in Venta and go past the wagon cage where Gregor is being held. Barlow recognizes them and figures that they need his help, and the trio explains that their friend was arrested for riding a horse. Galen points out that Gregor did it to save his life, but Barlow warns that Zaius won't be interested in pardoning someone for helping a fugitive, and explains that he can go back to his home town if he keeps his record clean. He says that the laws protect humans because everyone believes that only apes know how to handle horses. Alan says that he's been riding horses since he was 7, and Barlow asks if he would be willing to prove his skill. If he does then they'll talk about Gregor.
Barlow takes the fugitive to a wild horse, Woda, that needs breaking. The prefect explains that no ape has been able to ride it, and Alan wonders why he should risk his neck. Barlow says that if Alan can ride it, then he'll help Gregor. Alan agrees and proceeds to bust the horse. He manages to stay on and the horse breaks out of the corral. Alan turns it around and rides back, and Barlow explains that he's been challenged to a horse race. He wants Alan to ride in the race, and will get Zaius to make an exception to let Alan return. If Alan wins then Barlow will convince Zaius to pardon Gregor. If Alan loses then Gregor dies, but Gregor will be shot anyway.
Galen goes back to Venta and sees Urko and Zandar ride up. He realizes that Urko is Barlow's challenger.
Urko visits Barlow's office and demands to know if he plans to use a human jockey. Barlow confirms that he's received permission from Zaius, and Urko says that all Barlow has done is make sure that Woda will lose. The gorilla demands to know who the human is, and Barlow claims that he claimed the human himself without giving a name. Urko suggests that they raise the stakes for all of Barlow's horses and lands. If Barlow wins then Urko will transfer him back to Kamak. Urko agrees, confident that he won't lose, and leaves.
Later, Barlow tells Pete and Galen about the new bet. Pete points out that Urko sees Alan then he will kill him. Galen is disappointed about the lack of honor, and Barlow warns that there are rumors that Urko cheats. Pete says that they should jiggle a few odds to get things in their favor and leaves. He makes a deep mud pit near the starting line, while Galen watches and claims that he can't be seen doing such work. Meanwhile, he carves a wooden noisemaker.
Alan gives Martin instructions on how to make racing horseshoes as light as possible.
Urko has his soldiers set a pit trap and cover it.
Martin wonders if Urko will kill Alan regardless, and Alan assure shim that they have a few tricks ready. The blacksmith warns that even if Alan wins, Urko will still kill Gregor. He plans to convince Urko to let him exchange his life for Gregor, but Alan warns that Urko doesn't make that kind of deal and he plans to win the race.
At the camp, Zandar tells Urko that he has a net set for the opposing rider. As Martin arrives with Urko's horse, he hears Urko telling one of his men, Zio, to shoot the human jockey if he's in the lead when he reaches Zio's position. Martin introduces himself and says that he can help Urko win the race by fixing Woda's horseshoes with wedges. In return he wants Urko to spare Gregor and spare Alan. Urko agrees and Martin leaves. The gorilla then tells Zandar to let Gregor go and then shoot him "trying to escape," and kill the human jockey regardless.
On race day, the townspeople turn out for the celebration. Urko and Barlow sit up to watch, and Martin signals to Urko that he's rigged Woda's horseshoes. Martin brings Woda up but there's no sign of Alan. The trio is watching from the brush, and Alan notices that Woda is antsy. Galen takes off, and Alan goes over to the horse. He's careful to hide his face, and Galen uses the noisemaker to distract Urko so he doesn't get a clear look. Meanwhile, Woda bucks Alan off into the mud puddle that Pete dug earlier. The mud coves his face, making him unrecognizable, and Martin insists that there's nothing wrong with Woda. Once he runs off, Alan finds the wedges and digs them out of the horseshoes.
An impatient Urko tells the shooter to start the race. Alan and Pete get the wedges out and Alan mounts up a few seconds behind Kagan.
Pete finds Martin and demands to know why he sabotaged the horse. Martin says that he made a deal with Urko and points out where Zio is, and says that Alan will die regardless.
Kagan and Alan make the first of three laps through the village, with Kagan in the lead. On the second lap Woda hits the covered pit and falls, knocking Alan off. Kagan completes the second lap, while Alan mounts up and follows him. A soldier drops the net on Alan, but he rides past and avoids it. The horses gallop through a stream and the water washes off Alan's mud covering.
As the horses come around on the final lap, Kagan beats at Alan with his whisk. Alan grabs it away, while Galen moves up to Zio and places a tiger scorpion on his shoulder. The gorilla knows not to move, and can only watch as Alan crosses the finish line first. Urko recognizes Alan and yells at Zio to shoot, but by the time Zio fires, it's too late. The crowd panics and runs, and Barlow claims that the fact his jockey was a fugitive has nothing to do with their bet.
The soldier releases Gregor and tells him to run, but Gregor refuses when he figures that something is wrong. Pete arrives and knocks out the soldier, and Alan rides up as Galen gets onto the wagon cage. They take off, and Urko and his soldiers ride after them. Alan leads them away and then doubles back once he loses their pursuers and joins his friends. Once they free Gregor, Pete and Galen send the wagon on and hide as the soldiers ride past after it.
Later, Urko finds Barlow on the road. Barlow feigns ignorance and says that he always pays his debts when he loses. Urko irritably says that the payment has been arranged, and Barlow tells him that he's back to Kamak. After the soldiers leave, the trio approaches Barlow. They call Martin and Gregor out, and Barlow tells them that they will live in Kamak with him... and Gregor isn't to ride horses when he's watching. Gregor shakes Galen's hand and leaves with his father and Barlow.
Written by Gadfly on Feb 13, 2017