Usagi and the others decide to go to the future to rescue the other Sailor Guardians and to help Chibiusa. Chibiusa uses her space-time key to open up the doorway to the future. They become separated from Chibiusa and wound up across a door Luna has recalled from a dream. The Guardian of Time, Sailor Pluto, guards this door. Pluto fights them until Chibiusa intervenes. Pluto grants Usagi and the others safe passage to the 30th century Earth. They see a large black crystal has robbed energy from all of Crystal Tokyo's citizens. Before they can reach the Crystal Tokyo Palace, the Boule Brothers, also servants of Black Moon, confront them and trap everyone inside a magnetic field from which they cannot escape, but are later defeated by Mamoru. Usagi and the others reach the palace. They come across Chibiusa's mother, Neo Queen Serenity, who is frozen in the crystals. Another Tuxedo Mask greets Usagi and the others.