The Amazing Interplanetary Adventures of Flash Gordon was a 26-episode radio serial adapting the Flash Gordon (comic strip). Recorded in New York and transcribed for broadcast on West Coast stations, the program aired from April 27 to October 26, 1935 over the Mutual Broadcasting System. As was common with radio serials, each installment was 15 minutes.
The final installment had Flash Gordon, Dale Arden and Dr. Hans Zarkov landing in a jungle, where they encounter another Hearst comics character, Jungle Jim (played by Matt Crowley), thus transitioning into Jungle Jim as the replacement series.
Much of the series followed the comic strip very closely, essentially adapting that week's Sunday strip to the radio.
The first four episodes run through the first year of the comic strip story very quickly, in order to catch up to the current story. The first episode breezes through the first ten weeks of the strip, and a long narration at the beginning of episode 2 covers the next five weeks "off-screen", finishing the first storyline, "On the Planet Mongo". The rest of episode 2 covers the first eight weeks of the next storyline, "The Monsters of Mongo".
By Episode 5, the radio series has caught up with the current storyline, "The Witch Queen of Mongo", and begins to follow the comic week-by-week.
- Episode 1. April 27, 1935. A new planet has entered the solar system and is on a collision course with Earth. Flash and Dale are held at gunpoint by Dr. Hans Zarkov, and forced into his rocket ship, where they travel to Mongo. Ming the Merciless forces Flash to fight his Monkey Men in the arena, but Princess Aura falls for Flash, and rescues him. The Lion Men attack Ming's palace in their Space Gyros. Flash befriends Prince Thun, and they stop Ming's wedding to Dale.
- Episode 2. May 4, 1935. After an "off-screen" adventure with the Shark Men, Flash and Aura are captured by Prince Barin, who is also holding Zarkov prisoner. Flash, Zarkov and Barin join forces to overthrow Ming. They burrow into Ming's palace, where they're captured and forced to do battle. Flash and Barin survive the ritual battle, but Ming sentences them into exile with the Hawk Men.
- Episode 3. May 11, 1935. Flash and his friends are imprisoned by the Hawkmen in the Sky City.
- Episode 4. May 18, 1935. Dr. Zarkov saves the Sky City, and the Hawkmen befriend the Earth people. Barin falls in love with Aura.
- Episode 5. May 25, 1935. Flash becomes the King of Kira, and is attacked by the Lizard Men. Queen Azura and her Magic Men capture Flash and Dale. Flash is drugged with lethium, which makes him lose his memory; he becomes Azura's consort.
- Episode 6. June 1, 1935. Zarkov and the Hawkmen try to rescue Flash from Queen Azura, and are threatened by the Cloud Men. Azura has Flash lead the fight against the Hawkmen.
- Episode 7. June 8, 1935. Zarkov and the Hawkmen fight against Flash and Queen Azura. Zarkov sends Captain Mars to spy on Azura.
- Episode 8. June 15, 1935. Flash leads the charge against the Hawkmen, but Zarkov protects them with an ice barrier. General Tahl recommends to Queen Azura that she demote Flash, and make him the leader in Flash's place.
- Episode 9. June 22, 1935. Tahl makes an attempt on Flash's life, but Flash forgives him. Flash throws an icicle bomb at Zarkov.
- Episode 10. July 6, 1935. The frozen Zarkov is revived. He and Dale plan to escape from Azura's palace.
- Episode 11. July 13, 1935. Zarkov and Dale use meat-roasting electrodes to fight Queen Azura, and take over her palace. They tell Flash that he's been drugged with lethium, and they force Azura to drink the drugged wine.
- Episode 12. July 20, 1935. Flash takes a lethium antidote, and regains his memory. He becomes the King of Blue Magic Land. General Tahl tries to attack Flash.
- Episode 13. July 27, 1935. Azura is kidnapped by the rebels, who are loyal to General Tahl. Dale and Flash find gas globes in the palace to defend themselves.
- Episode 14. August 3, 1935. General Tahl and the rebels attack the palace with a dissolvo gun.
- Episode 15. August 10, 1935. Flash, Dale and Zarkov are forced to flee the palace. Zarkov creates a Light machine, which turns Flash invisible.
- Episode 16. August 17, 1935. The lethium dose has worn off, and Azura regains her memory. As "the Avenging Shadow", an invisible Flash enters the palace and tricks her into drinking Lethium again.
- Episode 17. August 24, 1935. Azura recovers her memory again, and Flash returns to the palace again.
- Episode 18. August 31, 1935. Dale is attacked by the Ape Men. Flash kidnaps Azura.
- Episode 19. September 7, 1935. Flash and Azura are attacked by Brown Dwarfs.
- Episode 20. September 14, 1935. The dwarves take Azura prisoner. General Tahl discovers the invisibility machine, and Zarkov is forced to destroy it. Flash saves Azura's life.
- Episode 21. September 21, 1935. Flash and Azura are forced to flee from the dwarves across a fiery pit.
- Episode 22. September 28, 1935. Zarkov rescues Flash and Azura.
- Episode 23. October 5, 1935. Dale wants to return to Earth, but Azura makes Flash the king of Cave World again.
- Episode 24. October 12, 1935. General Tahl tries to overthrow Azura, and put himself on the throne.
- Episode 25. October 19, 1935. Flash, Dale and Zarkov return in a rocket ship to Earth, where they crash in the jungle. They meet Jungle Jim.
- Episode 26. October 26, 1935. Flash and Dale are married in the jungle. The Flash Gordon series ends, and the show transitions into a Jungle Jim series.
- Flash Gordon: "Don't be frightened, Dale. The plane has crashed, but we're safe."
- Dale Arden: "Yes."
- Dr. Zarkov: "I know you for what you are -- Spies!"
- Ming the Merciless: "Slaves... Bring forward the Earth people!"
- Princess Aura: "This way, Earthman! This way! Here, to my balcony!"