Necrozma fully emerges from the Ultra Wormhole and pursues Lunala as the Ultra Guardians and the Aether Foundation staff watch on. After seeing Necrozma drain Lunala of its Ultra Aura, Professor Burnet realizes that Necrozma is responsible for absorbing Alola's Ultra Aura. Kiawe sees that Lunala and Necrozma are headed towards Melemele Island. At Lusamine's command, the Ultra Guardians mount their Ride Pokémon and fly after Lunala and Necrozma.
Meanwhile, at Team Rocket's food truck, Meowth spots Lunala and Necrozma flying around and tries to get Jessie and James to look, but they aren't motivated to do so. Meanwhile, aboard the Team Rocket helicopter, Matori and Gozu are becoming lax from the Ultra Aura depletion. Meowth calls them, and Matori demands to know what is happening. After Meowth tells Matori that Lunala and Necrozma appeared above Melemele, she has Gozu set course for Melemele Island. Jessie asks if they are going to catch it, and Matori clarifies that she and her Matori Matrix unit will before cutting the transmission. Jessie rants about Matori's attitude and vanity before returning to her exhausted state. Meowth becomes worried that if Matori succeeds, she will get a promotion and be able to boss them around even more, but his attempt to use this to motivate his teammates fails.
Hala and his Hariyama grow concerned as Lunala and Necrozma appear above a Melemele beach. Lunala is able to get away thanks to Tapu Koko who blocks Necrozma’s path. Despite being hit by a Dazzling Gleam, Necrozma continues to pursue Lunala. The Ultra Guardians arrive on the scene as Necrozma launches a Psycho Cut, but Lunala dodges and retaliates with Moongeist Beam. Necrozma isn't fazed and hits Lunala with another Psycho Cut. Lunala fights back with Moonblast and Air Slash, then uses Phantom Force to ambush Necrozma. Lunala attempts another Phantom Force, but Necrozma attacks with Metal Claw, which Lunala dodges, only to be hit by another Psycho Cut, sending it into the ocean. Ash and Gladion have their Garchomp and Noivern use Dragon Pulse and Boomburst on Necrozma. The interventions only angers Necrozma who unleashes Prismatic Laser on the Ultra Guardians, causing Lillie to fall off Altaria. Lunala swoops in and saves Lillie. Kiawe, Mallow, Sophocles, and Lana have Charizard, Flygon, Metang, and Dragonair use Flamethrower, Fire Blast, Flash Cannon, and Ice Beam respectively on Necrozma, but it is still unfazed and attacks with more Prismatic Laser, forcing the Ultra Guardians to retreat. However, Poipole is fixated by Necrozma and Rotom soon realizes that Necrozma's back features the same Prism Star symbol that Poipole drew before, meaning that Necrozma may be connected to the "Blinding One". Necrozma grabs onto Lunala and starts absorbing its Ultra Aura. Rotom also notes that Necrozma might be trying to possess Lunala itself. Gladion Noivern use another Boomburst and a Bite attack, but Necrozma shakes them off which causes Gladion to fall off of Noivern. While Ash catches Gladion, Necrozma splits itself up and merges with Lunala, becoming Dawn Wings Necrozma.
Soon after, Matori Matrix's helicopter ensnares Dawn Wings Necrozma in an electromagnetic net, but it breaks free. Another Ultra Wormhole opens up and Nebby emerges from it. Ash is happy to see Nebby again and hugs it. Nebby turns its attention to Dawn Wings Necrozma and attacks it, but Dawn Wings Necrozma counters with Prismatic Laser. Then, Nebby hits Dawn Wings Necrozma with Sunsteel Strike, which causes Necrozma to separate from Lunala and fall into the sea. Ash cheers at Nebby's win, but the weakened Lunala falls onto the beach. Nebby rushes to Lunala's side, but it is attacked by the helicopter. Despite a female grunt's concerns, Gozu calls for another electromagnetic net deployed at maximum power. The electromagnetic net captures Nebby and Lunala, but Gladion and Ash have Silvally and Pikachu use Air Slash and Thunderbolt on the net, freeing the pair. Nebby attacks the helicopter, forcing it to retreat. But then, Necrozma recovers and targets Nebby. It grabs onto Nebby, splits up its body, and merges the parts onto the latter's body, becoming Dusk Mane Necrozma. Dusk Mane Necrozma opens up and Ultra Wormhole and goes through it. Ash tries to chase after Dusk Mane Necrozma, but the Ultra Wormhole closes before he can go through.
Meanwhile, back at the Pokémon School, Professor Kukui and Samson Oak are sleeping, when suddenly, they are revitalized. Back at Team Rocket's food truck, Jessie and James also get their energy back and drive off to go find Lunala and Necrozma. On board the Matori Matrix helicopter, the crew is thinking about just giving up, when they suddenly feel normal and reactivate their aircraft's optical camouflage to wait for their next chance. The Aether Foundation staff arrive at the Ultra Guardians' location, and they bring Lunala back to the Ultra Guardians base to heal. Lusamine reveals little about Necrozma and simply refers to it as UB Black. The Ultra Guardians are relieved to see that the adults are feeling better as Kukui and Samson Oak join them at the base. Burnet and Wicke return from the medical room and reveal that Lunala's treatment is complete, but it will need time to recover its strength.
Ash remembers that the mural at the Altar of the Sunne had an image of Necrozma on it, and Lusamine states that there might be a connection between the "Blinding One" and Necrozma. Rotom asks Poipole why it drew the symbol, and Poipole attempts to explain, but no one can understand it. Then, Faba runs into the room with data on the helicopter from earlier, revealing that it belongs to the Matori Matrix, an elite unit of Team Rocket, angering Ash. Faba notes that they'll have to take the Matori Matrix into account in their counter strategy against Necrozma. Lusamine leaves the Ultra Guardians to watch Lunala as the adults go to plan the next stage of action.
The next day, at sunrise, the Island Kahunas visit their respective ruins: Hala at the Ruins of Conflict, Olivia at the Ruins of Life, and Nanu with Acerola visit the Ruins of Abundance; where they pray as their islands' respective Guardian deities watch. Back down in the Ultra Guardians base, the Ultra Guardians watch as Lunala sleeps. Just as Ash proclaims that he will help save Solgaleo, the group's Z-Rings and Z-Power Rings glow orange and the energy surrounds Lunala who soon wakes up from its recovery. The Ultra Guardians watch on as Lunala spreads its wings and shatters the medical room's glass.