The chapter begins with Olimar waking up to find the Plasm Wraith looming over him, with the rest of the party facing the creature down. It angrily retreats, leaping off the Comet Observatory and transforming into a meteor as it absconds. Olimar turns to find his entire family present, wife and alien dog included. Rosalina explains what happened while Olimar was trapped and unconscious, recounting how they had figured out that the Wraith reacted negatively to his loved ones, and so they had made the trip to Hocotate in order to retrieve them. Olimar's Wife claims to have come to help look after the kids, and not for Olimar's sake. Olimar discovers that the Pikmace has carried over into the real world from Magicant, apparently his to continue wielding.
Rosalina shows off a map of the world on the Comet Observatory's monitor, revealing that most of the world had been uncovered by plasm. Elise notes that the capitals of Hoshido and Nohr are holding out, but the plasm is quickly closing in around them. Rosalina explains that three areas remain largely free of plasm: Dream Land, Hyrule, and the Mushroom Kingdom: the latter has bits of plasm here and there, and thus the party resolve to go there to try and clear it out. The map shows that Peach's Castle had fallen to the plasm.
The Comet Observatory pulls over beside Peach's Castle, outside of which a massive battle is taking place between Peach's and Bowser's armies. The party decides to join the fray and help out Bowser given that Peach's side appears to be made of plasm. They quickly encounter the Elite Trio, who the party begins to question but is cut short when a retreat order is given from Kammy and Kamek overhead. The entirety of Bowser's army begins to fall back. Olimar notices Luigi, running for his life with an angry Mario in hot pursuit. The party retreats to the Comet Observatory as Bowser's army falls back to Bowser's Castle via their airships.
Once safe aboard the Observatory, Luigi and the Elite Trio explain the events that had transpired in the Mushroom Kingdom. Due to the encroaching plasm, Bowser had originally planned to take the Star Rod. But upon arriving at Star Haven, he found the place overtaken by plasm with the Star Rod and its guardians, the Star Spirits, absent. With this plan having failed, Bowser sent some scouts out to search for strong survivors across the World of Smash while the bulk of his troop staged an assault on Peach's Castle, hoping to defeat Plasm Peach and cut the problem off at its source. Meanwhile, Luigi had been preparing to head to Eagleland to deal with King Boo, but upon hearing that Peach's Castle had fallen, he rushed back only to find that Mario had been turned to plasm.
The group arrives at Bowser's Castle for a strategy meeting. In addition to the party, there was also Toadsworth, Bowser, Bowser Jr., five of the Koopalings(Lemmy and Iggy excluded) and the two Magikoopas. Iggy arrives in his airship, having found some new recruits while out scouting: Leaf, Snake, Dai Goroh, Zola, and Tom Nook.
With the whole team having been assembled, Bowser reveals his plan: to track down the Seven Star Spiritsand uncover the whereabouts of the Star Rod. He explains that they sealed themselves off in seven separate locations so as not to fall prey to the plasm: Dry Dry Desert, Booster Tower, Lavalava Island, Seaside Town, Nimbus Land, Gusty Gulch, and Toad Town. The entire mass of characters is split off into seven groups and sent to find the Star Spirits, with Bowser Jr. staying behind to watch over Bowser's Castle.
- Angsty Surviving Twin: Luigi after the death and subsequent plasmification of Mario. Perhaps downplayed in that they're fraternal twins.
- Big Badass Battle Sequence: Averted, as Bowser's forces are forced to retreat as soon as the party joins the fray.
- The Bus Came Back: Dai Goroh finally makes another appearance, after having arguably been the first person to join Olimar, if only on a technicality.
- The Caretaker: Marlia is this, and Olimar's failure to adhere to this trope is the source of her frustration with him.
- What Happened to the Mouse?: Olimar's alien dog, Bulbie, is never seen or heard from again. Perhaps Boney subsumed him.
