The 999 finally arrives at Prometheum, the planet factory of machine bodies. But as Tetsuro makes his final decision, he learns a startling truth about Maetel.
The planet Pluto is a graveyard for the human bodies people sacrificed to become machine men. Its machine caretaker, Shadow, desires Tetsuro to find and retrieve her own human body.
Hanako takes Tetsuro to the planet Wildflower, where her parents reside. She tells them Tetsuro is her fiancé, soon to be married... something he doesn't know about.
On a heavily industrial world, the freedom fighter Clowmaria is trying to halt industry for the sake of conservation. As a fugitive, she seeks escape on the 999.