Pokémon Adventures, Vol. 16 by Hidenori Kusaka

Ruby and Sapphire go their separate ways to achieve their dreams in just eighty days! But their paths keep crossing... While Ruby seeks a beautiful new Pokémon in Dewford Town to help him win Pokémon Contests, he runs into Sapphire who is challenging the local Gym Leader to improve her Pokémon Battle skills. Together, our intrepid Trainers attempt to deliver an important letter. What does it say and who is the mysterious recipient...? Plus, can Ruby and Sapphire prevent evil Team Magma from stealing a strange new technology?!