Carl opens by admitting he made a rash mistake. When Samantha says she almost has "him," Carl assumes Samantha will teleport back alone, but instead Samantha brings Claude Sludgington the Fourth, a huge borough boss from Fort Freedom, directly into Carl's group. The sudden arrival scatters everyone: Donut and Mongo are thrown into the trees, Areson is knocked aside, Carl tumbles down the slope, and Holger and Samantha are vomited out of Claude's mouth.

As Carl reads Claude's description, he realizes the creature is a powerful lightning-shooting amphibian boss with an important weakness: its stomach. Claude begins attacking blindly while still disoriented, swallowing a bush elf and firing eye-lightning around the area. Carl tells Donut to pull Mongo back and prepare to attack only when Claude is flipped over. In the middle of the confusion, Carl hears fighting and dinosaur roars from farther away, showing that the wider battle around Fort Freedom is still escalating.

Miss Nadine charges Claude, and Areson climbs onto the monster's head trying to damage it. Claude then fires lightning at Miss Nadine, who is directly between Carl and the boss, and the blast kills her instantly, exploding her body across the hillside. Carl keeps trying to direct Areson away from the creature's head while Samantha, swallowed again, insists Samantha will kill Claude from inside.

Carl casts Protective Shell intending to roll Claude onto its side, but because Carl is too close and on the wrong angle, the expanding sphere launches the entire monster straight into the air instead. Donut rides in on Mongo and, at Carl's command, hurls a fireball into Claude's exposed belly as the boss falls. The fireball tears open Claude's stomach and ignites the wound. Claude lands on the shield, slides into the trees, and becomes temporarily stuck while screaming and shooting wild lightning in every direction.

With the shield about to fail, Carl and Donut attack the open stomach with missiles and magic missiles. Mongo then charges directly into the wound. When the shield disappears, the bent trees spring back and fling Claude toward Carl. Carl cannot escape and is smashed into the creature's belly wound, nearly suffocating and suffering serious injuries. Mongo claws his way through Claude's insides and out the back, accidentally hurting Carl further, but the damage is enough to finish the boss. Carl heals himself, drags himself free, and Claude finally dies.

After death, Claude's body loses its magical cohesion and explodes into gore. Holger survives, the swallowed bush elf is dead, Areson is alive and angry, and Donut watches in disgust from a branch above the mess. Samantha lands on Carl's lap, soaked in gore, and cheerfully claims credit for killing the monster, ending the battle with a grotesque but important victory.