Xros Heart arrives in the Lake Zone. As they pass through a forested area, they find that the local Digimon frozen by the Bagra Army and Taiki hears a sound similar to the one that led him to Shoutmon. The sound leads him and Shoutmon to a lake where a group of PawnChessmon tell Taiki that their leader, Knightmon, is drowning in the lake after a defeat by the Bagra Army. Knightmon tells Taiki that he had been looking for a human General, but that it is too late for him. Taiki jumps into the ice-cold lake and is able to save Knightmon, but needs to be rescued himself by ChibiKamemon. Back on the surface, Akari chews Taiki out for being reckless for the umpteenth time and walks off. Taiki reloads Knightmon, who is good as new. Akari begins to realize how much she wants to go home and finds her phone's display acting up. Knightmon decides to bring Taiki and the others to Bastia Castlenote to meet the princess.
Meanwhile, Tactimon and Blastmon discuss the former's failure to take the Magma Zone just as Baalmon shows up to inquire after Lilithmon's whereabouts. Blastmon directs Baalmon to the Lake Zone, which is under siege by IceDevimon. IceDevimon's troops close in on the castle's last line of defense, but are ambushed by Xros Heart. Shoutmon tries to introduce himself in an over-the-top manner, but gets his thunder stolen by Knightmon who introduces Taiki instead. Xros Heart and the remaining defenders of the castle. Inside the castle, Knightmon brings the members of Xros Heart to Bastemonnote . Knightmon recommends making Taiki captain of the guard, but Bastemon reveals that she was planning to give the position to Kiriha, who walks in. IceDevimon returns to his base only to be berated for incompetence by Lilithmon. Baalmon walks in and offers to deal with Taiki to impress Lilithmon.
The Digimon of the castle hold a feast to celebrate their victory. Outside, Kiriha tells Taiki that he will be the one to take the Code Crown, but Taiki thinks that Kiriha has a personal issue of some sort. When Zenjirou asks about Taiki's habit of helping others, Taiki tells him about a time he didn't help another boy when he was younger. The boy had refused his help, but had to be hospitalized for several months for a serious injurynote . Taiki resolved afterward to never refuse to help anyone. IceDevimon's forces suddenly attack in greater numbers and with better tactics than before. Shoutmon is unable to help as he passed out from eating too much. Kiriha counterattcks by DigiXrosing Greymon and MailBirdramon into MetalGreymon. Taiki realizes that IceDevimon has infiltrated the castle with a group of Icemon to find the Code Crown. They attempt to capture Bastemon, but Shoutmon is able to stop them long enough for Taiki and the other Xros Heart Digimon to get back to the castle. IceDevimon absorbs the Icemon to grow larger and takes the battle to the roof. Shoutmon and the others are unable to hit IceDevimon, who freezes Ballistamon and grabs Knightmon, and things are further complicated when Baalmon ambushes them. Kiriha fights Baalmon in the air while Taiki DigiXroses Shoutmon with Dorulumon to get the Dorulu Cannon, which Shoutmon uses to free Knightmon. Knightmon in turn does a combined charge with the PawnChessmons to wound IceDevimon, driving him off. As IceDevimon's forces retreat, Kiriha concedes that Taiki was the better strategist this time and decides to let him have the Lake Zone.
Inside, Taiki collapses from exhaustion and Akari throws Shoutmon to cushion his fall. As Nene's Monitamon look on, Shoutmon realizes that they now have no leader and cannot DigiXros. Meanwhile, Lilithmon decides to try a new strategy with a much larger Digimon.
- An Ice Person: IceDevimon and his Icemon, which are an ice-themed variant of Gottsumon.
- Animal Stereotypes: Bastemon sleeps very frequently and curls up like a cat. In the dub, Knightmon adds to this by saying that she claws the furniture and coughs up hairballs. Bastemon was even dreaming about a ball of yarn.
- Beam Spam: MetalGreymon hits IceDevimon's army with a very big one.
- Bullet Seed: The Icemon and IceDevimon fire ice chunks this way.
- Cat Folk: Bastemon.
- Combination Attack: How Knightmon and the PawnChessmons are able to drive IceDevimon off.
- Dynamic Entry: Pulled off twice by Shoutmon and once by Baalmon. MetalGreymon even gets in on the action.
- Eye Catch: The one with Agumon and the rest.
- Fusion Dance: This episode introduces MetalGreymon.
- Got Me Doing It: In the dub, Taiki starts talking like Knightmon briefly as a one-off joke.
- Harmless Freezing: Happens to many of Knightmon's troops before Xros Heart arrives as well as to Ballistamon. Knightmon himself gets partly frozen. The latter two get better.
- Large Ham: The dubbers once again give IceDevimon a Christopher Walken-esque voice.
- Make My Monster Grow: IceDevimon does this by absorbing his remaining Icemon.
- Oh, Crap!: Shoutmon is the first to realize that he and the others can't DigiXros with Taiki out of commission.
- Our Vampires Are Different: Actually seems to be averted, despite what Bastemon's lore says in the broader franchise.
- Shipper on Deck: Knightmon is this for Taiki and Bastemon in the dub, much to Akari's chagrin.
- Ship Tease: Akari is very clearly jealous of Bastemon's advances toward Taiki. Naturally, it's played for comedy.
- We Need a Distraction: The large force sent by IceDevimon is just a distraction so that he can infiltrate the castle.
- Ye Olde Butcherede Englishe: Knightmon's formality is changed to this in the dub. He lapses out of it when his emotions get the better of him, occasionally leading to Sophisticated as Hell (well, as heck anyway).