Return of the Radium Rangers

The fifth Rick Rhodes serial was intended as Pinnacle’s most ambitious space adventure to date. Scripted once again by Rhodes’ creator Ron S. Burrows from his own novel, Return of the Radium Rangers would have seen Pinnacle’s production designers at their most creative, bringing visions of Saturn, Venus and Mars to the screen.

Ron S. Burrows photographed at Spenser Packard’s estate in late 1945
Photograph courtesy of Amelia Burrows

Burrows wrote only one more chapter play, penning the unproduced, lyrical Invaders from the Winter Star, before abandoning science fiction for a successful career as a contemporary novelist.

For ease, we have suggested how the serial’s cast could be represented on the tabletop.


Return of the Radium Rangers marks the triumphant return to space of Pinnacle Pacific’s most famous hero, Rick Rhodes. Blazing a trail across the Solar System and through fifteen amazing chapters of high adventure, Rhodes battles to save the Earth against the sinister forces of Zenara, War-mistress of Saturn, Champion of Neptune and Conqueror of Pluto.

With her mind bent on conquest, Zenara has built huge Gravitron Generators on Mercury, Venus and Mars. As the planets orbit the sun, they move toward a deadly alignment around the Earth. Their gravity distortion devices begin to cause massive disturbances in our world’s gravitational field, threatening to pull the planet apart. The moon wobbles in its orbit, volcanoes erupt, tsunamis deluge the coasts and great cities crumble into ruin. Within seven days the gravitational forces will be so great that all human civilization on Earth will be destroyed, leaving the planet ripe for invasion. Only Rick Rhodes can stop Zenara’s tyrannical scheme.

Production Notes

As Pinnacle Pacific’s flagship production for 1948, Return of the Radium Rangers makes extensive use of stock footage for Chapter One and existing special effects sequences shot for Rick Rhodes in Rhodes to the Stars, Radium Rangers, Rick Rhodes in Pirates of Luna City and Rick Rhodes and the Masters of the Atom.

The Venice Amusement Pier has already agreed to lease back to us the rocketship props from Masters of the Atom. Retrofitted with elements from The Wrath of Dr Xenon, the Luna City sets can double for Zenara’s capital in the rings of Saturn. The zoo sequence in Chapter Two reuses cages and costumes from The Devil’s Triangle with some brief location work at Jungleland. Lost city sets currently in use for The Legend of Harker Barnes are suitable for the Martian ruins in Chapter Ten. Most of the action on Mercury, Venus and Mars can be filmed at Bronson Canyon in Griffith Park.

Re-using stock footage and sets frees resources for building six machine men for Zenara’s mechanical army and the ‘trolley-worm’ horse costumes the Art Department is confident it can deliver to bring genuine otherworldliness to the sand-riders. Jack’s special effects team can use the techniques pioneered for Whale’s The Invisible Man to shoot the hounds. The mudmen costumes will be vulcanized rubber steeped in bentonite clay. Jack has a supplier downtown offering favourable rates for bulk orders.

The simmering sea sequence can be shot in James Brate’s pool once principle photography wraps on The Island of Peril. There is a coracle in storage from Valley of Mists that is suitable for the mushroom boat. The fungal forest and the Mudman island sets are the main sources of expense. Both can be constructed on Stage 1, and costs recouped possibly by hiring the set to Columbia for Congo Bill.


Old friends and new allies work together to defeat a tyrannical cosmic dictator.

  • Commander Rick Rhodes is the gallant leader of the Radium Rangers, a group of heroic pilots and commandos dedicated to defending Earth against any threats from space. Rhodes is inventive, intelligent and courageous. He is also a diplomat, capable of building alliances between diverse peoples as audiences will remember from Rhodes to the Stars and Masters of the Atom (Space Ace).
  • Rhodes’ protégé and trusted subordinate, Lieutenant Barbara Hunter is a veteran of deadly encounters with space pirates and mad scientists. More at home in military fatigues than a cocktail dress, she is nevertheless an attractive, disarming young woman. Her loyalty is unquestionable, and her practical, direct approach has saved Rhodes on more than one occasion. Her admiration for her commanding officer borders on attraction but as his junior she remains professional in all things except, perhaps, for an occasional lingering glance (Rugged Veteran).
  • Michael “Butch” Turner is Rick’s right hand man. In addition to being a skilled engineer, he is a tough and uncompromising Radium Ranger with significant combat experience. He is dedicated to Rick, Barbara and defending the Earth. He would give his life willingly for any or all three, but not without fighting for very last breath in the face of the enemy (Grease Monkey).
  • Cold, cruel and single-minded, Zenara, War-mistress of Saturn, Champion of Neptune and Conqueror of Pluto, is an unredeemable despot. She rules her people with an iron fist, using her duty to protect them as justification for subjugating and conquering other peoples in the Solar System. She is willing to sacrifice anyone to further her objectives, including her doggedly faithful lieutenant, Captain Laskin (Alien Tyrant).
  • Captain Laskin is commander of Zenara’s Royal Guard and master of her legionaries, grenadiers and centurions. His fanatical devotion to Zenara makes him a deadly adversary. He is, however, rather better at following orders than thinking independently or strategically (Ruthless Lieutenant).
  • King Thoran is ruler of the conquered Ice People of Neptune. A hulking bear of a man, Thoran is determined to overthrow Zenara, liberate his people and win back his throne. He understands that cooperation with the Earthmen is the best way of achieving this and commits himself to their cause enthusiastically (Renegade Royal).
  • The slender, sinister-looking Prince Shanti is a member of the deposed ruling family of Nightfolk on Pluto. Despite appearances to the contrary, Shanti is a quiet, moral and reflective man. A skilled swordsman and a cunning tactician, he is, like Thoran, committed to ending Zenara’s reign of tyranny in the Solar System (Rebel Leader).
  • Agak, chief of the sand-riders of Mercury, is the servant of his people, a man who prioritises the good of the tribe above all else in a hostile, unforgiving land. He rarely gives his loyalty easily, but when he does, he is a fierce and capable ally (Tribal Chief).
  • The ruler of a selfish, malignant species, Gor, King of the Mudmen of Venus, is in thrall to Zenara, who has promised him mastery over the marshes and swamps of Earth in return for assisting her forces guarding the Gravitron Generator. When Rick and his companions arrive on Venus, Gor sees this as an opportunity to prove his loyalty (Mudman).

Return of the Radium Rangers, first publication
Astounding Stories of Interplanetary Adventure, April 1945


A ruthless alien war-queen threatens Earth with destruction.

After Getheon’s sun exploded, only the city of Yul survived, lifted into space on massive anti-gravity engines. Under the command of Zenara, Getheon’s ruling war-mistress, Yul travelled through space until it reached Earth’s Solar System. By the time it entered Saturn’s orbit, the city was starved of supplies and its people were close to revolt. Sensing her domination was at risk, Zenara conquered Neptune and Pluto, using their resources to repair and sustain her city. Slowly, these resources became dangerously depleted and she resolved to subjugate Earth to provide a new home for her people – under her authority. Zenara’s knew her forces were too few to conquer Earth so, using her scientists’ advanced skills in gravity-engineering, she had Gravitron Generators constructed on Mercury, Venus and Mars to lay waste to Earth’s human population. With Earth now buffeted by wave after wave of gravimetric distortions, Rick Rhodes and his Radium Rangers fly to the rescue.


  • Rick Rhodes – Carl Linden
  • Barbara Hunter – Jane Rogers
  • Michael “Butch” Turner – Jack Morgan
  • Zenara – Pris Lawton
  • Captain Laskin – James Mulally
  • King Thoran – Alexander Richards
  • Prince Shanti – Pierce James
  • Agak – “Big” Brick Johnson
  • Gor – Monty Shore



With the Earth experiencing earthquakes, tidal waves and devastating floods, Rick Rhodes and his Radium Rangers are sent to investigate the origin of a mysterious signal emanating from Saturn. This signal is being broadcast to Mercury, Venus and Mars, the three planets causing the gravimetric disturbances threatening humanity. As the Rangers’ squadron approaches Saturn, a fleet of rocketships attack. Only Rick’s superior flying skills save his ship; the rest are destroyed by the enemy vessels. As he attempts to save himself, Barbara and Butch, their rocketship is caught in a magnetic ray and dragged into the rings of Saturn. Powerless, the craft is drawn down to a landing platform in Yul, Zenara’s floating capital. Arming themselves before leaving the rocketship, Rick and his companions fight a fierce battle with Zenara’s legionnaires before they are overcome by anaesthetic gas.


Rick, Barbara and Butch are brought before Zenara, War-mistress of Saturn. The Earth people try to fight their way out, but they are overpowered by Zenara’s guards. She proclaims Barbara and Butch suitable specimens for her menagerie since, in seven days, they will be the last surviving humans in the universe. A different fate awaits Rick. Recognising his military skills, the War-mistress orders him taken to her chambers. There, she activates the mind-altering Fascinator to secure his loyalty. As Rick’s mind begins to crumble, Butch and Barbara find themselves caged and surrounded by hideous aliens on all sides.


Rick is about to succumb to the Fascinator when a mysterious power loss causes the machine to fail. Zenara goes to investigate, leaving Laskin, Commander of her Royal Guard, to watch Rick. With his manacles deactivated, Rick overpowers Laskin and goes in search of Zenara’s menagerie. Imprisoned in the zoo, Barbara and Butch discover they have allies amongst the aliens and creatures locked in the other cages around them. Zenara has been conquering the outer planets and confining their usurped rulers in the menagerie for months. When Rick arrives to free all the prisoners, King Thoran, ruler of the Ice People of Neptune, and Prince Shanti, one of the ruling Nightfolk on Pluto, explain Zenara’s plans. Shanti knows that the Generators on Mercury, Venus and Mars are controlled from a vault at the heart of the city, but it is too heavily defended to attack. The Generators themselves are vulnerable, however, because Zenara’s forces are stretched thinly across the Solar System. Resolving to travel to Mercury, Rick, his companions, and the freed prisoners are about to escape when Zenara’s forces arrive. Captain Laskin releases protoplasmic horrors to devour the escapees.


Trapped between Laskin’s forces and the protoplasmic horrors, Rick and his allies seemed doomed until King Thoran uncovers an escape tunnel leading through the bowels of the city. They flee into the subterranean depths, pursued by the Zenara’s servants. The protoplasmic horrors slither after them, catching any stragglers in their horrid tentacles. Thoran explains that, when he was first captured, he was part of a work detail charged with cleaning the tunnels and knows them well. He leads them to the landing platform where Rick’s rocketship is under guard. Prince Shanti tells them that Zenara uses a Gravity Vortex to open a safe passage for her ships through Saturn’s rings. Shanti promises to open a vortex tunnel for Rick and then destroy the machine. If he survives, he plans on starting a rebellion against Zenara’s regime. Rick promises to return to aid him after the Gravitron Generators are destroyed. To buy time for Shanti, Rick and the others recapture their rocketship and hold it against Laskin’s men. Laskin readies a devastating tripod cannon.


As Laskin prepares to fire, the swirling rings of Saturn part to allow Rick’s rocketship to escape. Triumphantly, they blast away from Yul, pursued by Zenara in her flagship. Hers is the only enemy vessel to launch before Shanti destroys the Gravity Vortex. Rick pilots the ship to Mercury where they pinpoint the location of the Gravitron Generator in a desert valley. They are about to destroy it when their ship is shot down by Zenara’s vessel. Rick lands the ship inside a cave. Leaving Butch and King Thoran to repair the rocketship, Rick and Barbara set out on foot to sabotage the generator. They avoid Zenara’s patrols but as they begin to cross an open desert, savage sand-riders astride great worm-like serpents surround them.

Bronson Canyon: the location of choice for many filmmakers looking for a desert environment. It features in several Pinnacle serials.
Image courtesy of the Sidney Barron Memorial Archive


Rick’s diplomacy wins the sand-riders over to their cause and he and Barbara are taken on worm-back to the riders’ caves. Their chief, Agak, describes how he has been fighting a losing battle against Zenara’s forces ever since they invaded and began building the Gravitron Generator. Armed with only stone knives and clubs, the sand-riders are no match for the ray weapons used by Zenara’s legionaries. Back at the rocketship, Butch and King Thoran battle a ragged group of beastmen hunting for food. Their foes vanquished, they return to their repairs. In Agak’s cave, Barbara realises that the materials they need to defeat the invaders and destroy the generator are all around them: sulphur ejected from Mercury’s dead volcanos, saltpetre on the walls of the caves in which Agak’s people dwell and carbon in the dead trees on the edge of the great desert. Together, Rick and Barbara teach Agak’s people to manufacture gunpowder. They are about to launch their attack on the generator when Zenara’s rocketship strafes the caves, burying Rick, Barbara and the sand-riders under tons of rock.


Barely escaping with their lives, Rick, Barbara and Agak lead the survivors through a narrow passage and out of the ruined cave system. The Gravitron Generator is located in a dry valley below, surrounded by the tents of Zenara’s soldiers. Armed with gunpowder grenades, Rick’s party sneak by the guards and plant explosive charges around the generator. They are about to set the fuses when Zenara’s ship lands, waking the encampment. Outnumbered and outflanked by Laskin and his legionaries, Rick lights the fuses in the hope that destroying just one of the generators might be enough to save Earth, even if it costs them their lives. He squeezes Barbara’s hand as they draw their pistols and face the onslaught.


A ferocious battle ensues. Rick and Barbara know their situation is hopeless but refuse to surrender. The explosives are about to detonate when Rick’s rocketship flies into view and strafes the area. Zenara’s forces scatter and her flagship is damaged. Rick cuts the fuses moment before they set off the charges. Butch brings Rick’s vessel down beside the generator to collect his companions. Rick tells Agak and his sand-riders to get clear of the area while they destroy the generator from the air. Agak agrees and, armed with the gunpowder grenades, leaves to fight a guerrilla war against Zenara’s soldiers. Rick takes the rocketship up and blasts the generator to pieces. As they leave Mercury bound for Venus, Zenara targets the accelerating rocketship and activates her Dimensional Ray. Aboard Rick’s vessel, strange distortions appear in the angles between banks of equipment. Reality tears and a pack of baying dimensional hounds pounce on the companions. Their ship spirals out of control into the cloudy embrace of Venus.


The rocketship crashes on the surface of Venus, its impact softened by a forest of giant fungi. Rick, Barbara, Butch and King Thoran defeat the last of the hounds but realise their vessel will never fly again. Butch manages to salvage the ship’s Gravitator, a device used to detect gravitational anomalies. Following the Gravitator’s signal, Rick leads his party through the fungal forest. Soon after, a thunderous roar heralds the arrival of Zenara’s rocketship. Exiting her vessel, the War-mistress uses a Sonic Subjugator to summon a swarm of flying fungi: repellent, vaguely humanoid winged things with an exposed brain. These horrid creatures pursue Rick and his companions, attacking them with a barrage of exploding spore pods. Barely avoiding these horrors, Rick’s party reach the edge of the forest and find themselves on the shore of a simmering sea. The island on which Zenara has built her Gravitron Generator is visible in the distance. With his friends, Rick manages to launch a giant, upturned mushroom cap, using it for a coracle as they paddle towards the island. They are almost at their destination when Zenara’s rocketship blows them to atoms.


Moments before Zenara’s attack, Rick orders his companions to abandon their makeshift boat. They plunge into the steaming waters moments before it is destroyed. Still following Butch’s Gravitator, they swim ashore, finding shelter in the inland swamps. When they pause to recover themselves, strange figures rise from the mire: dripping, formless entities that speak in sepulchral tones. Barbara escapes unseen, but the rest find themselves prisoners of the Mudmen of Venus, allies of Zenara who assist the garrison of guardsmen protecting the generator. The Mudmen take Rick and his friends to Zenara, whose rocketship now rests beside that of her men. Rick tells Zenara that Barbara is dead, encouraging her to gloat over her prisoners. She explains that they have barely delayed her plans. Once she has dealt with Rick, Butch and Thoran, she plans to return to Yul and send a force to rebuild the generator on Mercury. Earth will be hers! As a reward to the Mudmen, she gives them Rick, Butch and King Thoran. Their King, Gor, decides to sacrifice them in honour of their god Oorz. In the shadow of the Gravitron Generator, Rick and his companions are tied up and slowly lowered into a lake of bubbling mud.


A mighty explosion rips through Zenara’s encampment as Barbara launches her attack. Armed with the remaining gunpowder grenades from Mercury and one of Zenara’s thermic rayguns, she cuts her way through to Rick, Butch and Thoran. Freeing them from their bonds, she drops her bag of explosives. Thoran retrieves it and the three men seize thermic guns for themselves. Together, the four friends set about overwhelming Zenara’s soldiers. The thermic rays have a devastating effect on the Mudmen, causing them to harden into outlandish statues that moan eerily. Fighting their way toward the garrison’s rocketship, Rick, Butch and Barbara are separated from King Thoran, who is surrounded by Zenara’s soldiers. Rick is about to go back for him when Thoran holds up Barbara’s explosives and, with a defiant grin, detonates them all. Thoran, the generator and most of Zenara’s legionaries disappear in a burst of fire. With no time to mourn their friend, Rick pilots the rocketship away from Venus. Furious, Zenara triggers the remote self-destruct device on Rick’s stolen vessel. It is consumed in flame.


With their rocketship disintegrating around them, Rick guides the stricken craft to the surface of Mars, where it crashes amongst the ruins of a great civilization. Butch manages to coax enough power from the ship to take a bearing on the location of the final Gravitron Generator before the systems fail and fire takes hold. The companions strike out across the barren world, dwarfed by the towers and plazas of a once-mighty city.

Remarkable model work for the Martian ruins by Pinnacle’s chief model-maker, Ed Harling. This is the only surviving photograph from the serial’s pre-production. Courtesy of Nat and Jayne Harling

Hearing Zenara’s rocketship approach, they take refuge in an empty building. Accompanied by their few surviving legionaries, Zenara and Laskin search for Rick from the air. Realising they will never find them among the ruins, Laskin lands their vessel. He is about to lead them in pursuit when Zenara stops him. Taking a control from her waist, she turns a dial and, from concealed alcoves, half a dozen mechanical men step forward to attention. Implacable, they march from the ship and stalk through the ruins, their electric arcs striking sparks from the tumbled buildings around them. Zenara, accompanied by Laskin and his men, follows behind. Seeing the mechanical men advance, Rick, Barbara and Butch make a run for the Gravitron Generator at the heart of the city. They run headlong into the garrison Zenara has protecting her machine. As Rick and his friends battle the legionaries, the mechanical men strike them down with their electric arcs.


Rick, Barbara and Butch wake as Zenara’s captives, guarded by her mechanical men. Zenara plans on returning them to her menagerie on Yul, not as exhibits but as mind-wiped examples of what befalls those who defy her authority. Apparently disowning his companions, Rick charms his way into a private audience with the War-mistress. He convinces her that he is completely defeated and wants nothing more than to serve such a great leader as she. Zenara’s ego prevents her from seeing the ruse and, as they talk, Rick pilfers the unit controlling the mechanical legion. When he displeases her, she orders Laskin to return him to Butch and Barbara. Butch examines the stolen unit and soon has control over the mechanical men. Taken by surprise, the War-mistress’s forces are routed. Laskin is killed and Zenara taken prisoner. Rick, Barbara and Butch then use the mechanical men to destroy the Gravitron Generator, ending Zenara’s plans to conquer Earth. As night falls and they return to Zenara’s rocketship, pale creatures emerge from the shadows and attack: they are the degenerate descendants of Mars’ once proud people.


Beset on all sides by Mars’ hideous denizens, Rick and his friends fight a desperate rear-guard action. Zenara breaks free and takes control of the ghoul-pack with her imperiousness. With a new force at her disposal, she drives Rick, Barbara and Butch into the ruins and prepares to abandon them on Mars. Horrified, they watch Zenara’s rocketship take to the skies. The ghouls close in around them.


Just as all hope seems lost, Zenara’s rocketship is shot from the sky and crashes close to Rick’s party. Repeated attacks from a second rocketship drive the ghouls back to their lairs. When the rocketship lands, Prince Shanti disembarks to arrest Zenara and rescue Rick, Butch and Barbara. Shanti explains that Zenara’s dictatorship has been overthrown and Yul is now a free city. Neptune and Pluto will soon be liberated. With Zenara their prisoner, they return to Yul, travelling along the restored vortex tunnel. When the War-mistress is brought before her own throne to face judgement, she sprints up the dais and activates the city’s doomsday device. Zenara escapes in the chaos that follows. With Yul doomed to destruction, Rick and Barbara organise a hasty evacuation. Rocketship after rocketship blasts away from Yul, streaking along the vortex tunnel. Rick promises the refugees they will be safe on Earth and, as he leads the fleet towards their new home, they watch the once-magnificent city disappear into Saturn’s clouds. A lone rocketship arrows towards Mars unseen.