Pokémon Omega Ruby & Alpha Sapphire Vol 3

From the VIZ Media edition

When Lorekeeper Zinnia launches an attack on Sea Mauville to prevent our friends from charging the Dimensional Shifter to protect the planet, Ruby attempts to steal her scroll and its secrets. Meanwhile, after learning the shocking truth about the falling meteor, Sapphire loses her voice. And then she is transported through a mysterious ring to where?! And what does Mythical Pok mon Hoopa have to do with all this ...?

Source: OpenLibrary