As Hareta and Piplup continue their journey, they come across their first clue to Dialga's whereabouts but realize that the leader of Team Galactic has beat them to it. In order to defeat him, Hareta and Piplup begin training under the Canalave City Gym Leader, Byron.
General Note
Translated from the Japanese.
Printed Manga-style: book opens from left to right; pages are read from right to left.
"First published by Shogakukan Inc. in Japan as Pokémon D: P pocket monster diamond pearl monogatari"--Title page verso.