The Inner Senshi are shocked that there are more Sailor Senshi. Sailor Uranus says that there was never any reason for the Inners to know. Sailor Chibi-Moon sees Sailor Neptune's mirror and remembers Michiru. She blurts out that the mirror is a tailsman. Sailor Mars remembers someone calling out to the talismans in her dreams and tells this to Neptune and Uranus.
Sailor Uranus is sympathetic towards the Inners because they too can feel the approaching destruction, but she says that she an Neptune will not fight with them. The two attack the Inners and escape.
Luna tells Usagi, Mamoru, and the girls about the Outer Senshi. Long ago, Sailors Neptune and Uranus lived on the outskirts of the solar system, "protecting the Silver Millennium from a distance." They were never supposed to come into contact with the Princess and her four soldiers, but something serious has drawn them to Earth. Usagi feels that they must be allies in this time if they guarded the Silver Millennium in another time. Minako angrily disagrees with her, saying that Neptune and Uranus attacked them just like enemies do. She wants to fight them the next time they come in contact. Quietly, Chibi-Usa tells Mamoru about the helicopter ride; she doesn't think the two can be enemies.
That night, Mamoru lays in bed. He reaches across Chibi-Usa's pillow and holds Usagi's hand. In his dreams, he sees a shadowy female figure with long flowing hair standing atop a ruined pillar. His eyes open at the same time as Usagi's. "That dream... the god of ruin..."
Rei prays at her fire and wonders where the other two talismans are.
The next day, Usagi sits on a bench in Ichionashi Park, waiting for Mamoru. Two hands cover her eyes, and she turns around expectantly. "Mamo-chan?" Instead of Mamoru, Usagi finds herself face to face with Haruka in her Mugen boys' uniform. Even though she approached Usagi, Haruka claims that the younger girl drew her there. She turns to go, but Usagi calls to her. She wants to know if Uranus and Neptune are allies, but Haruka won't tell her. Finally, Usagi gets to the question that's been haunting her for some time: "Haruka-san... Are you a man? Or else, are you a woman?"
"A man, a woman... Is it that important?" Haruka leans in close to Usagi, their noses touching. At that moment, a very shocked Mamoru enters the park. "The Prince appears," Haruka says as she runs away.
Mamoru runs up to Usagi and hugs her. He asks if Haruka (who Mamoru still thinks is a man) did anything to her. Usagi says no, but she starts crying.
Chibi-Usa bursts into the Game Center looking for Mamoru. The girls and Motoki tell her that he's not there. Chibi-Usa is disappointed because she wanted him to help her with a clay sculpture for school. She shows everyone her unfinished work; it looks a little like an urn. She tells the girls that it's supposed to be the Legendary Holy Chalice. When no one knows what that is, she explains that she and Diana used to sneak into Neo-Queen Selenity's room and look at all her treasures. One of the treasures was the Holy Chalice, a special cup that helps the Queen keep her youth. "When a crisis calls for it," explains Diana, "wondrous power flows from the Chalice."
Chibi-Usa says good-bye and goes to Mamoru's apartment, hoping to catch him there and rope him into helping her shape her urn into a chalice.
At the apartment, Mamoru loosens his tie and pours Usagi a cup of coffee. They drink in an uncomfortable silence. Usagi thinks that he is angry about seeing her with Haruka and tries to explain. At that moment, Chibi-Usa bursts into the apartment with such enthusiasm, both do spit-takes with their coffee. She notices that they are not their usual selves, and she demands to know if Usagi has cheated on Mamoru. Usagi vehemently denies this, but she secretly wonders if this is what Mamoru thinks.
Chibi-Usa unwraps her sculpture and asks Usagi and Mamoru to help her transform it into the Holy Chalice. Both are skeptical, especially Usagi, since she doesn't even know that a Holy Chalice is. Mamoru takes out a book and reads from it: "'During the Holy Communion, you put the wine anbd holy water into [the Holy Chalice]. Your body is purified, and you're given strength.'" Chibi-Usa likes the picture in the book, and wants to put jewels on her version. Usagi suggests she uses beads, and Chibi-Usa sends her to the store to get some.
When Usagi comes back, she brings the beads and ice cream. Mamoru has already worked the urn into a more believable chalice-shape. Usagi and Mamoru press the beads into the clay, and call Chibi-Usa over to see. Chibi-Usa, however, is asleep on the floor.
Usagi puts her arms around Mamoru and rests against his back. She apologizes for making him think something was going on with Haruka, and she admits that she is jealous of Michiru. Mamoru says that he was jealous too. He pulls her in front of him and hugs her. Chibi-Usa peeks out from under the blanket and smiles.
In school, everyone is talking about how Ami got a perfect score in every subject again. Ami is depressed because it's raining again, while Usagi is depressed because it's midterm time. Ami suggests that they all go to the new prep school to study. The new prep school, Mugen Prep School, teaches the brightest students. Makoto shows Ami the city-wide ranking: Ami is second after a Mugen student, Bidou Yui.
The prep school teacher welcomes Ami to the class. He says that is Ami ranks in the top twelve, she can earn a full scholarship to Mugen Gakuen. When Ami sits down, a girl with white hair wearing a Mugen uniform introduces herself as Bidou Yui. She invites Ami on a tour of Mugen the next day.
The girls are nervous about Ami going into Mugen Gakuen. Minako is convinced it's a trap, but Ami promises to contact them if anything goes wrong.
Inside Mugen Gakuen, Ami is directed to the thirteenth floor to the science class. Yui is waiting for her, standing beside a glass case. Inside the case, a black mass swirls. Yui tells Ami that the mass is a model of the Tau star system that she made for a science experiment. She then excuses herself to take a class.
Kaolinite looks at Ami from her pool of water. She senses power coming from the girl and fears that she is a Sailor Senshi. She tells Yui, now a Witch, to take care of her. "By my system, the level 202 Viluy, I will obtain the souls of the Sailor Senshi."
Ami trows a pen at a security camera and shatters the lens. She runs through a door marked "Underground Laboratory. No entry." Haruka and Michiru watch her run down the stairs.
In the lab, Viluy catches up to Ami. She brings brainwashed Mugen students with her. Haruka and Michiru appear to save Ami, but Viluy just orders the students to capture all three of them. Ami knocks the students away and contacts Usagi. She then leaps out of the window to escape. During the fall, she transforms into Sailor Mercury and plunges thirteen stories into the swimming pool.
Michiru and Haruka also jump from the window, but they leap into the branches of a nearby tree and hide in the leaves. They agree that they can no longer attend Mugen Gakuen and work undercover.
Sailor Mercury uses her Mercury Aqua Mirage on Viluy, but the Witch counterattacks with Mosaic Buster. She sends nanorobots to dissovle Sailor Mercury's skin. However, the Inners come to her rescue. Just as Sailor Moon is about to use her heart moon rod, Haruka and Michiru transform. Sailor Uranus reveals the second talisman, her Space Sword, and kills Viluy.
At KO University, Motoki invites Reika out for a drink, but she says that she has to do a mineralolgy study. She leaves him to go inside to the labs. Inside an old office, Reika sees a young woman with dark hair and skin. She introduces herself: "I study basic physics with a major in theoretical physics. I'm Meiou Setsuna. Nice to meet you."