|“||Attention people of Earth, Attention people of Earth this is Krankor exploration force speaking!||„|
|~ Phantom of Krankor|
The people of Krankor are an invasion force of a planet called Krankor AKA the dark planet. The people of Krankor seek conquest of planets and have the weapons to dwarf most planet's defenses. What the Krankor lack though is an efficient fuel source. When the Earth professor, Maki, invents a new fuel source for rockets the invasion force of Krankor mobilize for Earth under their military commander The Phantom to get it for themselves.
When the invasion force of Krankor arrive they make their presence known to Earth by jamming their television transmissions and broadcasting an ultimatum on all channels. The Ambassador Phantom of the Planet Krankor announces that he and his people have come to make demands and will arrival the following evening at exactly eight-o'clock, He states that the people of Japan will comply or be destroyed before ending his transmission.
Dr. Maki begins answering questions the mourning following Krankor's transmission. Dr. Maki has already come to conclusion based on the timing and the technology of the Krankor's ship that while the people of Krankor's weaponry is advanced and their transport capabilities have advanced to intergalactic travel their fuel source is by far inferior to that Japan's new fuel source which he had recently created. Based on what Maki saw in the transmission he estimates that with the fuel used by just one ship they could have launched a fleet of one-hundred if they'd had his fuel source.
As The Phantom of Krankor announced he and his forces land the following night at eight-o'clock exactly. The military personnel standing by to meet them are instantly vaporized by the ship's weaponry. The Phantom announces that the people of Earth are no match for Krankor's technology and demands that Dr. Maki hand over his fuel source or Japan will be destroyed.
The night after the Phantom make his demands he sends the people of Krankor to seize Dr. Maki's research but is met by the masked super hero, Prince-of-Space. The Prince announces that Krankor's weapons will have no effect on him and to leave without causing anymore problems or he will be forced to defeat their entire invasion force. Krankor laughs off the threat and instructs his men to blast the costumed Earthling. Battle with the Prince proves his threats well placed and the people of Krankor quickly realize they will need to treat Prince of Space as a major threat for their invasion force. The people of Kranor fall back to their ship to plan their invasion force more carefully.
The Krankor invasion force steps up their plans the following night by raiding Dr. Maki's research center. The squad incinerates security and make their way to the to the main office where they force Dr. Maki's assistant to reveal the location of Maki's formula by threatening to harm some local children. Unfortunately for the Krankor invasion squad the children are under the personal protection of the Prince of Space, who make a appearance once again to foil Krankor's invasion plans. The Prince of Space again proves Krankor's weapons useless against him and gains possession of the formula, leaving it behind with a note for the children to return it to the lab while he pursues Krankor's troop.
Despite the perceived victor The Phantom had a back-up plan, while the Prince of Space is chasing his men as decoys The Phantom abducts Dr. Maki himself. The Phantom threatens to destroy Dr. Maki and his loved ones if he does not cooperate but informs him that he will have time to think about it as the space-craft returns to Krankor. As the flag-ship begins to leave Earth The Prince of Space's vessel is spotted following them but The Phantom orders the ship to bombard it with fire. The Prince's ship quickly sustains several hits and is forced disengage pursuit. Between the bombardment and asteroid-field The Phantom is content that if the Prince is not killed he will at the least be unable to follow but orders a small team to stay behind to find the wreckage and make certain the Prince is dead. The flag-ship then continues on until the ship reaches it's home planet and the Phantom's palace. The Phantom palace is watched by his faithful monster Bannin (The Guardian), a giant mutant which appears dim but viscous. The Phantom soon calls out Maki along with other scientists abducted from around the world to put their talents to use for him. In light of their situation The Phantom of Krankor is confident they realize the seriousness of their situation and tells them they will start in their service to him by warning their home world to stand down it's future resistance for their own good. The Phantom once again hijacks the airwaves to broadcast to Earth putting Maki on to back up the hopelessness of the situation, however Maki mid-way through the broadcast tries to warn the people to keep fighting even without him but is cut off quickly by Krankor. The Phantom continues to make demands and impress upon the people of Earth how out matched they are.
As the broadcast is being seen by the people of Earth The Phantom's troops have located Prince of Space, whose true identity is that of a simple boot-black. Thanks to a device called the X-radar the troops are able to discover the Prince's secret identity and go to finish him off as he returns home. The Prince has his children take-cover as he dawns his costume and confronts the troops as they arrive. The Prince once again proves that Krankor's weapon's are useless and engages them in hand-to-hand-combat. The Phantom arrives to attend to the situation himself and retrieves his men as they return for the flag-ship.
The Phantom summons his captives upon his return as he reveals their fate. The Phantom shows the scientists his palace and Bannin as he passes by stating that the heart of his domain is the last thing they shall ever see. The Phantom tells Dr. Maki and the others that they will be sealed in space pods and shot into space at random locations where they will drift endlessly or perhaps be drawn into a star if they are lucky. A messenger quickly darts in to inform Krankor that this time the Prince of Space has followed them back to their home-planet. The Phantom turns on the great-halls monitor to see the Prince's ship dodging Bannin's fire-breath and after some quick maneuvers defeats it with several precise laser blasts to the creature's face. As Bannin falls the Prince's ship beings it's decent to Krankor's palace nut Krankor turrets open fire as the ship disappears from the view screen.
The Phatom starts with Maki as the first to be launched but his men are soon attacked by Prince of Space who has survived and has made his way into the great-hall just in-time to save Maki. The Prince again proves he can not be harmed by Krankor's weaponry and quickly forces The Phantom to flee as The Prince frees Maki and the others. The Prince and scientists begin making their way to The Prince's ship while the Prince fights of the people of Krankor. The Phantom traps the Earthlings and tells them to wait there while is off to destroy Earth and that he will returns shortly to destroy them.
The Prince was in-fact counting on the Phantom and his remaining troops to flee as he announces that their ships will be the only way bavk home and if they want to return home they'd need to stowaway. The Prince then blasts through the cell and leads the scientists to the ship. Though the Phantom spots them and tries to seize the scientists as human shields his troops are quickly felled in open combat with the Prince. The Phantom flees as his troops are destroyed only to find that the Prince has rigged his own weapons, the Thorium bombs, to blow. Krankor's palace crumbles around him and crushes The Phantom. Dr. Maki and his fellow scientists are able to escape before the explosion while the Prince's one-man-ship takes off beside them and escorts them home.