The final installment in the Ar tonelico series. The story takes place in Sol Cluster, a kingdom ruled by an organization called Clustania and their ultimate goal Ar tonelico Qoga: Knell of Ar Ciel - Play-Asia.comis to enslave humans and rule the world. However, the two key Reyvateils (humanoids) they need to accomplish their goal meet Aoto and fight back against injustice.