After escaping from Prince Diamond, Sailor Moon and Tuxedo Mask return to Crystal Palace. Sailor Moon tries to awaken Neo Queen Serenity with the Imperium Silver Crystal, but it doesn't work. Thinking there is now no way to save her, Rini runs off, but encounters Wiseman, who reminds Rini that it was she who took the Silver Crystal causing it to disappear, and telling her that Serena and the other Sailor Scouts don't love her.
As more energy is put into the Dark Crystal's energy reactor, Sapphire tells Emerald that the Dark Crystal is extremely volatile and fragile, and that Diamond doesn't know this, but Wiseman does, and is very suspicious of him. They try to warn Diamond, but he seems not to listen due to his love for Sailor Moon distracting him. Emerald is extremely jealous of Diamond's love for Sailor Moon, and goes to see Wiseman, asking him for power to help her invade Crystal Palace. Wiseman says that Emerald can be the queen of Crystal Tokyo, with Diamond as her king, and creates a dark crown for her from the Dark Crystal. Emerald suspects a catch, but takes the crown anyway, and is transformed into Queen Emerald, increasing her power. However, just as she had been worried about earlier with there being a catch, when Wiseman says that everything has a price, to Emerald's horror, it proves too powerful for her, causing her to collapse and fall unconscious, before being absorbed and transformed into a gigantic dragon.
Emerald attacks Crystal Tokyo, and the king tells Tuxedo Mask and the Sailor Scouts that the dragon has a humanlike mind inside. The Sailor Scouts go to fight Emerald. Sailor Venus uses Venus Love Chain Encircle on her, scratching her, but the cut heals. However, she does appear to be wounded nonetheless. Emerald attacks the Sailor Scouts with her tail. Sailor Jupiter uses Jupiter Thunderclap Zap on Emerald, seemingly killing her, but she is barely even damaged and tries to eat Sailor Moon, who is saved by Tuxedo Mask. Sailor Mars uses Mars Celestial Fire Surround, hitting Emerald directly but not affecting her. Sailor Mercury freezes her tail with Shine Aqua Illusion, but she shatters the ice.
Tuxedo Mask reminds them that the king said that inside, the dragon has a humanlike mind. As Emerald breathes fire at Sailor Moon, Tuxedo Mask saves her and throws a rose at her crown, stunning Emerald and seriously weakening her. Sailor Moon destroys her with Moon Scepter Elimination. She briefly reappears in her original form, surrounded by a ghostly light and revealing her true identity to everyone, before she vanishes for good, falling into a dark void to her death, saying Diamond's name.
As the king informs everyone that Rini has vanished, Wiseman comments on Emerald's awful laugh and saying good riddance to her before adding on that he plans to kill Diamond and Sapphire as well.
- Final appearance of Emerald.
- It is hinted that Wiseman has his own evil plans.