This volume opens with precocious and rapidly growing Hotaru under the care of Setsuna, Haruka, and Michiru. They are seeing to her education as well as her nurturing, now that she's alone. During a violin lesson taught by Michiru, the ghost of pegasus manifests around Hotaru, and then all the classmates watch as a spirit Sailor Chibimoon chases him through the house until he collapses, dead. She falls to her knees and weeps over him. Young Hotaru realizes that she recognizes the girl from pictures in photo albums around the house and is sad that the girl is so overwrought over the death of the pegasus.
Some time later, Chibiusa is brooding over Elios at home. She wants to go to him to help, but she doesn't even really know where Elysian is. Usagi comes back from visiting Mamoru, but she seems to have become infected with the same thing that's troubling him. The sickness of the Dead Moon is upon her and she cannot be contacted by the other senshi who are in dire straits at the hands of the Amazon Quartet. Fortunately for them, all four outer senshi show and save their keesters. They're still in hot water, but Usagi's condition keeps them from contacting her. Saturn concentrates deeply and manages to connect with Chibiusa whom she calls "Small Lady." Chibiusa looks at Neptune's Deep Aqua Mirror which lies unattended on her dresser and sees the four outer senshi inside it and knows that they've returned. She tells Usagi who urges her on, so she transforms into Super Sailor Chibimoon and sends the Deep Aqua Mirror back to Neptune who immediately puts it to good use.
As she runs across town in an attempt to get to the senshi, Chibimoon notices that the town is dark and in serious disrepair. Random mobs are forming and brawling on the streets. Clearly, something is Not Right. Chibimoon, Super Sailor Moon, and Tuxedo Kamen arrive on the scene of the collapsed evil circus tent at the same time. Zirconia works some hoodoo on Usagi and Mamoru and turns them into children. Chibimoon is so pissed by this point that she curses like a little sailor and runs off with Sailor Saturn after Zirconia. The Amazon Quartet catches them and Saturn is forced to open a can of whupass on them. She eventually brings them to their senses, so Zirconia imprisons them in some stones and then proceeds to trap Saturn and Chibimoon in the shards of glass from a broken mirror.
Meanwhile, Elios has managed to revive Mamoru and Usagi as adults, only they are now in Elysian. He explains that he had a revelation as soon as the invasion started that he should look for a maiden who is a princess and a soldier, protected by the moonlight, who carries the crystal that can break the hold on the Golden Crystal. The person delivering this message identified herself as "Princess Lady Serenity" and looked remarkably like a seventeen-year-old Small Lady.
Elios helps Usagi and Mamoru get back to the surface after Usagi decides that the Golden Crystal they're searching for is inside of Mamoru. Together with the senshi, minus Saturn and Chibimoon, they go to fight Zirconia, but the power is too strong and they begin to be overcome. Elios wraps the rest of his power up in one desperate wish to free them and then passes on with an image of Chibiusa in his mind, saying that he's happy to have met the small maiden. This part makes me cry ;_;