Above the ruins of New Helic City, two Storm Sworders fly over, piloted by Rosso and Viola. Van and Irvine continue to battle the Helcats, though they are seriously outnumbered. Irvine proposes that they run, given that they won't make it if the Death Stinger fires its Charged Particle Cannon. Van says they have to force their way out--the Blade Liger and Lightning Saix charge for the screen of Helcats. As they run, the beam is fired, wiping out all the Helcats. The two Storm Sworders swoop down from above, grabbing the Saix and Liger using grappling hooks, saving them. They are soon dropped off on the Ultrasaurus, which has since made its way far out to sea. Van is then greeted by Fiona, who warmly embraces him, happy that he is safe. Van then asks Herman's permission to come aboard, which is granted.
Everyone attends a meeting. Herman debriefs everyone about their vessel, the Ultrasaurus, the largest Zoid to have ever been constructed, but virtually unarmed. Moonbay yells at him, asking why "her" Ultrasaurus is left defenseless. Herman asks them to stay focused, and informs everyone that they will be headed to the Empire to pick up a new weapon. Schubaltz introduces the Gravity Cannon, the largest, most powerful gun with a barrel more than 50 meters long and 16 meters wide. Camford assures everyone that she has faith in them all.
Van and Herman visit Krueger in the hospital wing of the Ultrasaurus. Herman tells Van a story about Krueger: a long time ago, he took a direct hit to his Zoid and ended up badly wounded. After that, he crawled across the desert in that state for a week, despite having ten broken bones. Krueger opens his eyes, affirming the story. He tells Van that his father saved him, and that's how the two met and became friends. He then tells Van to support Herman fully, as he's the best man to take over the command of the Ultrasaurus.
Elsewhere, in the Empire, a Gustav enters a lab hidden with optical stealth mechanisms. Inside, Dr. D stresses over the completion of the Gravity Cannon. He gets up to make himself a cup of coffee, complaining that his assistant always forgets to add salt. Emperor Rudolph, accompanied by Prime Minister Homalef, greet Dr. D. Rudolph marvels at the Gravity Cannon, while Dr. D explains that it's the only weapon that can match the Charged Particle Cannon. However, he warns Rudolph that he's only been able to make three shells for the cannon.
Deep in the ocean, a Hammer Head sent out from the Ultrasaurus is caught in a rising cloud of matter and explodes. Herman concludes the substance to be Methane Hydrate. Everyone is drawn to a meeting by Herman, who informs them about Methane Hydrate. He explains that under intense pressure, Methane gas is capable of combining with water to form Methane Hydrate. O'Connell tells everyone that there's a massive amount of it spread along the sea floor, and promptly furthers the demonstration, setting a small sample they have on fire. Herman says that this "Fire Ice" is susceptible to environmental changes, thus can give off methane gas when it breaks down. O'Connell suspects that the Hammer Head got itself caught in the bubble that exploded when it ignited. Because of this danger, Herman wants to take a longer route, despite the time loss. Everyone seems to be in agreement with this plan. Suddenly, the alarm goes off. Fiona reports that several Sinkers, sent by Hiltz, are headed straight for the Ultrasaurus.
Herman orders everyone to their battle stations. Van in his Blade Liger, Irvine in his Lightning Saix, Thomas in his Dibison, and Schubaltz in his Iron Kong MK II report to the flight deck to repel the aerial invasion. The Ultrasaurus deploys the few weapons it has, including anti-air guns, and underwater anti-torpedo missiles. Moonbay manages to dodge a few stray missiles headed for the Ultrasaurus' neck, to everyone’s relief. As everyone battles the Sinkers, Hiltz's Death Stinger approaches from underwater.
Meanwhile, the Imperial laboratory comes under attack by Redlers and Stealth Vipers. Luckily, Rosso and Viola, in their Storm Sworders, arrive in time to repel the invaders and save the Gravity Cannon from destruction.
Fiona detects a large object approaching, which turns out to be the Death Stinger. She tells Herman they have three minutes until they come in range of the Charged Particle Cannon. O'Connell reports that all the Zoids have been stored below deck, so Herman gives the order to initiate a dive. As the Death Stinger brings its Cannon up above water to fire, Moonbay seals the water-tight compartments and the Ultrasaurus dives, barely escaping the beam. Moonbay is relieved that they can't be hit by the Cannon while underwater.
Van and Thomas want to take Hammer Heads out to battle Hiltz, but Herman stops them. He proposes luring the Death Stinger into the Methane Hydrate fields. He asks permission from Camford, who tells him that he is in charge. With confirmation, he gives the order to change course. The Death Stinger closes in.
Schubaltz approaches Herman, telling him that if his plan is crazy but brilliant; if they succeed, he'll owe him. Herman seals the deal, and Fiona reports that the Death Stinger is approaching. As they come to the ice fields, Hiltz uses the Death Stinger's massive claws to punch through the Ultrasaurus' armor, tearing through and allowing the sea water to infiltrate. Herman gives the order to release the Ultrasaurus' depth charges, causing the Methane Hydrate to become unstable, release the methane gas, and explode. The Death Stinger is carried away by the bubbles, but the Ultrasaurus emerges unscathed.
Everyone celebrates. Herman congratulates everyone on their hard work, and tells them they'll continue on towards the Empire. The episode ends with the Ultrasaurus sailing off in the sunset-colored ocean.
- Blade Liger
- Lightning Saix
- Iron Kong
- Hammer Head
- Death Stinger
- Storm Sworder
- Stealth Viper
- Instead of cutting out a section of the episode that references to/shows alcohol (as is usually done), the dialogue in one scene was simply changed to avoid mentioning. Herman and Schubaltz end up making a deal after the decision is made to enter the Methane Hydrate ice fields: in the Japanese version, Schubaltz offers to treat Herman to a glass of alcohol if they make it out safely. In the English dub, Schubaltz simply says that he'll owe Herman.
See also: Zoids: Guardian Force