Sequel to the third Ar Tonelico game.

Planet Ar Ciel has been finally regenerated. Five years have gone by since that day, but the people of Sol Cluster still continue living in the Third Tower.
Right now, the lifespan of Tilia, who is also the Third Tower herself is coming to its end. Sol Cluster is plunged into chaos now they have to face her death, which also means the disappearance of the Tower. To save the people, Aoto and the others have started a plan of extending Tilia’s lifespan, but doing this means she will undergo a tremendous suffering.
A completely original story showing what happens after the popular PlayStation 3 RPG of the same name. Characters from the first two games also make an appearance and provide their help as everyone faces together the Third Tower’s disappearance. So, what will be Tilia’s final fate…?