Playing with a toy train, Akira and his new found friend are interrupted by a phone call from the boy's father, who informs that he will be over shortly to pick him up. Unfortunately, the engineer's plans are terminated when he is attacked on the road by a pair of disguised Garoga agents. Firing a canister from a strange bazooka like gun, the car was engulfed in magenta hued smog. In seconds the man and vehicle where both gone, transported away. Hours passed before Jo and the boys receive a call from the man’s work asking if he has arrived yet. When they discover that he is missing the Japanese detective immediately head back to the Sakimori’s home and informed the family. Immediately Hikaru become suspicious and suspected that the war-like Garoga aliens had a hand in the man’s disappearance.

Elsewhere in Japan, the rest of the Baron's invasion forces were continuing to build their underground base, as a small team was preparing for the arrival of an important Middle Eastern world leader that would be arriving in Japan. Detective Jo, Akira, and Hotaru intercepted the important figure and tried to escort him safely away. Sadly for them, the Garoga were two steps ahead. Stopping them at a road block, the human guised enemies of Earth blasted the ambassador’s vehicle with a canister that swallowed the car in lavender smoke. Hikaru was close behind in pursuit in his car, but was too late to help them. Yelling “Zone Power!” the young man transformed into Zone Fighter and took the Mighty Liner vehicle into the alternate dimension from which his family and friends had disappeared to.

The Gold Garoga was immensely angered once he learned that his agents had brought the two Zone Family members with them. They had endangered the plans and had to be punished. With no care or pity, the maniacal beast blasted the groveling minions, setting them ablaze. Grunting in satisfaction the gargoyle creature moved on to tape record information that he was going to pry out of the human engineer. Seeing a chance, Hotaru unhooked her Zone Communication device and tossed it away. Her actions did not go unnoticed, though, as the captain alien howled in rage and proceeded to beat the woman as she was still strapped helplessly to her chair.

After receiving the S.O.S distress message from Zone Angel, Zone Great told Akira to transform and take Smokey to their aid. Immediately the youthful warrior complied and converted to Zone Junior. Using the technological spaceship, the child flew into the alternate dimension in hopes of finding his sister in time. Meanwhile, the human captives had finally broken free of their enslavers. Jo led the little boy and father up to the surface, as the newly transformed Zone Angel battled with the red eyed Gold Garoga.
Outside, four Silver Garogas surrounded and made quick advances on the attempting to escape humans. But Zone Fighter, whom had just arrived, intervened and transformed the murdering creatures into ash with a single laser blast. He wasted no time before doing his Astral Dash and teleported to help his sister battle with the last of the outer space invader. Unable to cope with both of the elder Zone warriors the aurous skinned Garoga grabbed a nearby microphone and pleaded with his commander to send the genetically engineered plant monster Dorola. Growling with dissatisfaction the Baron complied and sent the Monster Capsule to Earth.

Once on the planet, Dorola instinctively went to attack Zone Fighter, who summoned his power and grew to match the alien creature's massive size. Zone Fighter battled with veracious intensity, but against the animal/plant kaiju’s toxic breath he found himself beaten. With his energy gauge flashing red, Earth’s hero was on the brink of defeat. Zone Angel and Zone Junior would not let that happen, though, as they beamed their power into the giant's energy capsule on top of its head. Given brand new life the hero went back on the offensive and with a combination of his Meteor Missiles and Side Chop slicing energy darts, the newest beast of Earth’s most fearsome enemy, was eliminated. After vanquishing the beast, Zone Fighter turned his attention against the Garoga’s underground base, turning the once technological base into flaming wreckage. When all was said and done, the Zone family returned the man and boy to his grieving wife and mother. A happy ending for everyone…except Baron Garoga.