Dead Moon Circus continues to threaten Usagi Tsukino and the Sailor Guardians. As Earth sinks deeper into darkness and nightmares multiply, the Outer Sailor Guardians become alarmed when they see young Hotaru Tomoe rapidly aging after a total solar eclipse. Believing their prince and princess are in danger, the four Outer Guardians reignite their powers and unite to support their comrades.
The eclipse worsens Usagi and Mamoru Chiba's conditions, draining their strength and leaving the Guardians unsure of their next step without their leader. Discouraged by this, Hotaru and Chibiusa decide to face the Amazoness Quartet alone, as the quartet has been the main source of recent upheaval. With Queen Nehellenia's imminent release, the Sailor Guardians must act quickly to stop her plans.