Following Makoto's capture, Luna and Mamoru discover one of Petz's Black Crystal earrings and have Artemis analyze. Frustrated by her failure, Minako proposes to Usagi and Mamoru that they talk with Chibiusa, who appears to made a friend named Momoko, only to have Chibiusa freak out upon seeing the earring.
As the other members of Black Moon become curious about their advisor Wiseman, Rubeus sends the final Spectre Sister, Calaveras, who uses her medium powers to call upon the power of her fallen sisters. As Usagi remains upset that Chibiusa refuses to tell her anything, her friends show her a DVD of Calaveras allegedly channeling session to lure out Minako.
Usagi discovers Chibiusa has taken her transformation brooch while Minako comes across Calaveras as she uses her powers to process others with the spirits of her sisters. Just as Usagi and Chibiusa are confronted by Rubeus, they are saved by Mamoru, who awakens his own power to stop Rubeus' attack. After Usagi comes Minako's aid and defeat Calaveras, Chibiusa explains that she comes from the 30th Century to seek Sailor Moon's help in saving her time.