The S.P.U. is the second highest point in the Tower of Ar tonelico, located right above the Prism Garden and right below the Rinkernator, and it's the facility that houses the Mainframe of Ar tonelico, the supercomputer that processes and maintains the Binary Field of the Tower and all of the SH Servers connected to it. Its acronym stands for Song Processing Unit, and due to its great importance, it's protected by an extremely powerful shield. It's the final area that can be accesed through the Dividing Gates, given that the highest sector of the Tower, Sector A9, has its dividing gate come out into this place.
Lyner Barsett and his friends arrived at this place after trudging through the Prism Garden, and they found Lyner´s father, Leard Barsett, prisoner in one of the rooms adjacent to the main chamber. Misha noticed how badly hurt he was, to which Leard remarked that he was barely alive. He wanted to tell them something, but Lyner urged him to stop talking until they took him to a safer place.
A few moments later, Lyner and his friends returned to the S.P.U. in order to claim the FFT Divider they needed to separate Mir from Shurelia. Lyner first tried to force his way through the shield, but he got pushed back and badly hurt. He remarked he was quite careless, and asked Misha/Aurica to sing her best healing song so he could withstand the shield for enough time to take the FFT Divider and get out of there. Aurica/Misha first rejected the idea, but she didn't have other option than to listen to Lyner when she was reminded that there wasn't any way of shutting down the shield they knew. Aurica/Misha then began singing the best healing song she knew while Lyner tried to penetrate the shield once more. He felt an excruciating pain as he forced himself through the energy layer, only being supported by Aurica's/Misha's song. However, when he was an step from reaching the FFT Divider, Mir noticed what they were trying to do, and sent her ELMA-DS virus and an squad of brainwashed ELMAs to annihilate them. Lyner took the FFT Divider and left the shield as fast as he could, briefly falling down to the floor in exhaustion, but he didn't have any time to rest because the viruses attacked at once.
After the battle, Lyner thanked Aurica/Misha for their help, while Jack asked why there were Guardians in this area. Misha then remembered that the ELMA-DS looked really similar to Shurelia's personal ELMA guardian, prompting Krusche to remark that most likely Mir based off her virus from Shurelia's guardian. Lyner cursed Mir for having the guts of taking over not only Shurelia's body, but also her Guardians, while Radolf urged the party to continue their ascention to the place where Mir awaited for them: the Rinkernator.
The S.P.U. is a rather small areas, although it has to be visited at least three times during the course of the game for different reasons. Due to its small size, it isn't much of a problem to go through it, and it doesn't have much in the way of treasures either, making it a rather easy experience in comparison to the excruciating length and difficulty of the Prism Garden.
Number of Random Battles in this Area: 10