Japanese Title: The DATS Team Annihilated!? Clash with Mercurymon
Having finally arrived at the Infinite Ice Ridge, the DATS agents are surprised to see an old man ice fishing like it’s the most normal thing in the world. Masaru explains to Tohma and Yoshino that this is the man who gave him his Digivice and who has been giving him advice up until now. Tohma and Yoshino are skeptical about who this man is and how he got into the Digital World, but Masaru trusts him implicitly.
Together they make their way into the caves, with the old man pausing to deal with a snooping Kuramon before they go inside. Within, they soon find their path blocked by a horde of Tsumemon, and a running battle ensues.
In Merukimon's lair, a Kuramon informs Gotsumon of the intruders. He rushes to the throne room to tell Merukimon that the humans have invaded. Ikuto, seeing this as a chance to put his own doubts to rest and prove himself a proud Digimon warrior, goes off to fight them with Falcomon. Gotsumon declares that he’ll go after them, though his intentions are less than innocent.
Elsewhere in the caves, the protagonists have lost the Tsumemon swarm. They come out into a yawning chamber, where they get their first look at Merukimon's actual domain: a spectacular ice palace. Tohma warns everyone to keep their guard up, since this wide-open space means they could be attacked from anywhere at any time. Sure enough, a giant boomerang heralds the arrival of Ikuto. The old man is shocked to see the boy and recognizes his name.
A battle ensues, during which Gotsumon arrives on his Yanmamon steed. Ikuto is happy to see him at first, but then Gotsumon starts using his Rock Fist to knock stalactites loose from the ceiling. When Ikuto and Falcomon demand to know what he’s doing, Gotsumon gleefully declares that he'll crush everyone here, the two of them included! The falling stalactites compromise the integrity of the caves, and a yawning fissure opens which swallows Masaru, Agumon, Ikuto and Falcomon.
Tohma and Yoshino dig themselves out of the rubble, only to discover that Gotsumon has taken the old man hostage. He demands that they throw down their digivices and surrender, which they do reluctantly. The old man is unperturbed, however, and tells Gotsumon that his boss will want to speak with him. Moments later, Merukimon's voice booms out from the ice palace, commanding Gotsumon to bring the prisoners to him.
In the fissure, Agumon and Falcomon come to on a ledge. Falcomon has sprained his wing, which prevents him from attacking Agumon while the latter's back is turned. Masaru hangs from the ledge by his fingertips. He could pull himself up, but he's holding onto Ikuto, who angrily demands that he be let go. The boy would rather save himself than be saved by an evil human. Masaru tells him to stuff it.
In Merukimon's throne room, the old man addresses the lord of the castle. the two speak as if they know each other, convincing Tohma that the old man must have been part of the original expedition to the Digital World. But while their conversation starts civilly enough, it quickly grows heated. The old man accuses Merukimon of sending Digimon to attack the human world in violation of the treaty between their worlds. This enrages Merukimon, who claims the opposite is true: it was humans who struck first, invading the Digital World with an army equipped with weapons that can permanently delete Digimon. The old man is shocked and proclaims that humans never did this, that they just want to foster peaceful coexistence, but Merukimon calls him a liar.
Masaru arrives, and in characteristic fashion, manages to punch Merukimon in the face. The DATS agents digivolve their partners to the Ultimate level. They attack Merukimon one at a time, but he shrugs off everything they throw at him and hits them back much harder. Masaru gets an idea, however: individually they may not be strong enough to beat him, but if they combine their powers they might have a shot. They do so: Lilamon's Lila Shower, MachGaogamon's Howling Cannon, and RizeGreymon's Shining Destroyer combine into a single beam which hurtles toward Merukimon. Alarmed by this display of power, Merukimon raises his arms to block the blast.
When the smoke clears from the explosion, the wall behind Merukimon has shattered, revealing a Digital Gate beyond. But Merukimon himself is barely hurt. A single singe mark on his right arm is all the damage they managed to inflict. That they even hurt him that much astonishes and enrages him, and he retaliates with a beam that slams the partner Digimon against the wall and knocks them all back to their Rookie forms.
It's at this dire moment that the old man makes his move. Pulling a digivice out of his pocket, he Realizes his partner Digimon: Kamemon, the turtle that hands out tea at DATS headquarters. Kamemon digivolves into his Champion form of Gwappamon and destroys the columns holding up the roof. Ikuto is knocked unconscious by the falling debris and Merukimon is forced to shield himself from the same, giving the protagonists time to act. The old man shoves Ikuto into Masaru's arms and tells them all to escape through the Gate.
Masaru refuses to go at first, but the old man shouts some sense into them: their Digimon are in no state to continue the fight, and if they stay they'll die. Shaken, Masaru does as he says. Falcomon flies after the protagonists and his unconscious partner.
Merukimon sees them all fleeing and fires another beam at them. The DATS agents barely manage to leap through the gate in time to avoid annihilation.
In the real world, a Digital Gate opens above the bay. The four humans and their four partner Digimon fall out, landing in the water. A spotlight falls on them moments later: Commander Satsuma has come in a helicopter to pick them up.
Tropes:
- Cavalry Betrayal: Gotsumon acts as if he's come to provide Ikuto and Falcomon with some much-needed assistance against the protagonists. Instead, he tries to kill them and the protagonists.
- Chekhov's Gunman: Turns out that goofy turtle Digimon who's been seen around DATS headquarters a few times is the old man's partner.
- Combination Attack: RizeGreymon, MachGaogamon and Lilamon combine their respective Rising Destroyer, Howling Cannon, and Lila Shower attacks into a single beam of energy. It proves powerful enough to damage Merukimon slightly and to shatter the wall behind him, exposing the Digital Gate that he uses to travel to and from the human world.
- Complaining About Rescues They Don't Like: Ikuto is furious that Masaru saved him since the latter is an evil human, and demands that Masaru let him go so Ikuto can save himself. Masaru does not oblige.
- Curb Stomp Cushion: The protagonists' Ultimate-level Digimon are no match for Merukimon individually, but they do manage to injure him slightly with a powerful Combination Attack. This just makes him mad, however, and he promptly hits them all with a mighty energy blast that drops them back to Rookie level.
- Deader than Dead: Discussed. Ikuto confirms that his mother, Frigimon, was killed in a manner that prevented her from reincarnating as a Digi-egg. Many other Digimon met a similar fate during the humans' attack on the Digital World.
- Foreshadowing: A lot of it gets dropped in this episode.
- Yushima is shocked to see Ikuto and recognizes his name.
- Merukimon reveals that a human army invaded the Digital World some time ago and massacred many Digimon using weapons that stop them from reincarnating. Yushima denies any knowledge of this, implying that another party unaffiliated with DATS was responsible.
- Merukimon notes that Masaru's DigiSoul feels familiar. When he hears Masaru's full name, he is shocked, wondering if Masaru is the son of Daimon Subaru, implying that he knew Masaru's father.
- Ice Palace: Merukimon's lair is revealed to be a palace made of ice hidden in the depths of a gigantic cave.
- Interspecies Adoption: Merukimon admits to having adopted Ikuto after his guardian Frigimon was killed. He calls Ikuto "the son I never had".
- The Law of Diminishing Defensive Effort: Merukimon makes no attempt to defend himself from the individual attacks of the Ultimate-level partner Digimon, which can't hurt him. When they combine their attacks into one powerful stream, however, he does try to block it, and is left with a small wound on his arm.
- That Liar Lies: Merukimon accuses Yushima of lying to him when the latter protests that humans never attacked the Digital World.
- Make It Look Like an Accident: Implied. Gotsumon tries to off Ikuto with the other humans by dropping stalactites on everyone, and later hems and haws when Merukimon asks him what happened to Ikuto.
- The Reveal: This episode confirms that the old man who’s always been giving Masaru advice was part of the original expedition to the Digital World ten years ago, and that Kamemon is his partner. It also reveals that a group of humans unaffiliated with DATS invaded the Digital World using weapons that could permanently kill Digimon.
- Rod And Reel Repurposed: Yushima uses his fishing rod to get rid of the Kuramon that's been spying on the protagonists. He hooks it right in the eye (with a suction cup, thankfully) and casually flings it away.
