Kaijuologists were stunned. Something strange was going on. Recently, a program was put in effect to place microchips under the skin of the creatures on Monster Island so that satellites could keep track of them, should any escape. They tested this new system for a week and it seemed to work fine. But then something happened. Two of the monsters, Varan and Manda, were missing from the island's complex. Even stranger still, the satellites meant to track these two were giving readings that said they weren't even on Earth any more. After hours of checking their instruments, they confirmed that they were working correctly.

But where were they? According to their data, they were where no one would have ever thought to look for them: Mars. Several satellites sent by NASA years before to study the red planet had confirmed it. Everyone was in shock. The two monsters were on Mars, near the icecap. How were they breathing? How did they get there? Pictures taken even showed that some of the ice had melted just enough to make a small lake. What was going on? Everyone's questions would be answered when NASA would record the epic struggle that was about to play into these strange events.

Varan landed on the shore of the lake and growled. He had been spending the last four hours searching his surroundings. He didn't know where he was, but he didn't like it. It was far too cold for his taste. Manda was on a cliffside, watching Varan. He didn't see the point in wasting his energy looking for a way out. They were stuck and there was no way out of it. He didn't know where they were, but his instincts told him that they were far away from home. Two objects in the distance caught Manda's attention. As they got closer, Varan stopped rampaging long enough to see that they were really four objects. Two UFOs hovered towards them. Below them, being carried by the twin craft, were Gigan and Megalon.

After a few moments, the UFOs unleashed the two kaiju and flew off. Before either monster hit the ground, a napalm bomb hit the mountainside, causing Manda to fall. Varan charged, attacking Gigan barely a second after he landed. Sparks flew as the dinosaur's claws slashed across the metal armor. Caught off guard by this sudden attack, Gigan toppled over. Megalon raised his spaded arm, about to strike, when something wrapped around his legs and caused the Seatopian god to fall on his back. Manda hissed as he lifted his tail up, Megalon in his coils, and twisted his body to throw Megalon headfirst into a mountain. When the smoke cleared, Megalon was missing.

Gigan was smacking Varan in the face as hard as he could with his scythes. Blood was pooling on the ground around the cyborg. Varan's face was bloody but he refused to stop his assault. The ground exploded as a drill slammed into Varan's side. Varan stopped his attack and howled in pain as blood splattered everywhere. Gigan blasted Varan in the face with his cluster beam, causing the beast to fall over. Gigan called out to his ally just as Megalon popped out of the ground. The two slammed their arms together and laughed. Manda hissed at Megalon, only to be blasted in the face by his horn lightning. Gigan shot out his grappling hooks. Varan felt his neck get tighter as Gigan pulled him in closer. Manda lashed out, wrapping himself around Megalon's torso, trying to squeeze the life out of him. Megalon couldn't move his arms. He could feel his body being crushed. The harder he tried to break free, the harder Manda squeezed him. The snake-like kaiju had his face dangling just mere inches away from Megalon's, taunting him. Left with no other option, Megalon spat a napalm bomb in the dragon's face, causing an explosion. His grip loosened enough for Megalon to break one arm free and slam it right into Manda's face, forcing the beast to fall to the ground. Manda looked up and hissed only to have Megalon kick it. Manda rolled away. Megalon shot a volley of horn bolts and napalm bombs, each explosion causing Manda to roll farther away.

He wasn't going to let the serpent get close to him again. Gigan, meanwhile, was wailing on Varan with a furry of scythe swipes. Varan was covered from head to toe in wounds. Gigan turned around, impaling Varan on his tail anchors and flying several meters before swinging his tail around. Varan slid off the tail blades and smacked headfirst into the same mountain Megalon had before. Varan shook debris off of himself as Gigan opened his chest ports, firing his razor discs. Varan opened the membranes that ran from under his arms to the sides of his legs and quickly scaled the mountain, barely avoiding the discs, before gliding into the sky. He looked back and saw that they were following him, then spotted Megalon as he kicked Manda into the lake. He nose dived at the giant cockroach, pulling up at the last second. One of Gigan's discs couldn't pull off the maneuver and slammed right into the giant bug's back. Megalon screamed as the disc dug into his flesh, greenish-yellow blood splattering everywhere. Megalon turned around to fire at Varan but ended up blasting the other disc by mistake. Shrapnel flew everywhere, tearing into the flying kaiju's back. Gigan shot another red beam from his cycloptic eye. Explosions covered Varan's body and he fell from the air.

Megalon turned his attention back to Manda and jumped in the lake, ready to drown the overgrown snake. What Megalon didn't know was that he was now in Manda's home turf. Manda slowly crept up behind Megalon, following him, waiting for him to get in deeper water. With the speed of lightning, Manda shot forward and wrapped all around Megalon's body and dragged him underneath the surface. Megalon's arms and legs were tied up as he sank to the bottom. Manda tightened his grip more and more. Megalon, in his futile attempts to escape, shot a barrage of lightning from horn and napalm bombs from his mouth, but Manda was wrapped too close for the weapons to find their target. After a while, Megalon's movements slowed down as he lost the energy to fight back. Within mere seconds, the Seatopian god was crushed, his guts flowing out of his corpse and filling the lake.

Manda slithered out of the lake covered in Megalon's innards when it heard Gigan shriek. The cyborg flew directly at the serpent, but Varan dropped out of the sky and landed right on top of him, clawing and kicking. Gigan's eye glowed red, but Varan delivered a headbutt hard enough to shatter it before the energy could be discharged. Now blinded, Gigan panicked, jumping right back to his feet. Manda leapt up and wrapped his serpent-like tail around Gigan's arms and forced them behind his back. His tail snaked around the machine's neck and pulled hard, exposing his throat. Varan turned around and slammed his tail into the cyborg's neck. Again. Sparks flew. Again. More sparks flew and this time he could see Gigan's neck was tearing. He turned around and bit down, his teeth punching through the metal. He put his claws on Gigan's shoulders, pushing with his hands while pulling with his jaws. Gigan let out one final shriek before his head was torn clean off.

Blood and oil poured out of his neck. A spark caused the oil to ignite. Gigan's neck looked liked a fountain of fire. Manda roared and Varan shrieked. A warning to anyone who dared to attack them.

Back on Earth, everyone was stunned when they realized that aliens were kidnapping their monsters and using them as weapons. The fight with Gigan and Megalon was just a test to see how useful Manda and Varan were. It was only a matter of time before they would invade the Earth.