Diamond and Pearl are preparing to help Platinum train Piplup for its upcoming battle with Roark. In a flashback to the day before, Roark returns to the mines, and impresses his mining crew with the fossils he found. Platinum appears and asks Roark for a battle. They agree to battle in two days time. Back in the present, Pearl comments on how strong willed Piplup is and decides to help Platinum train. Platinum comments on her knowledge of type advantages, but claims that reading and experiencing are two different things. Diamond starts practice battling with Platinum in preparation for the upcoming gym battle. They assign Platinum and Piplup a training regimen to help prepare.
The next day, the group arrives at the Oreburgh Gym. A trainer challenges Platinum to a battle, and Diamond and Pearl get kicked out of the gym by a statue for giving Platinum advice, and eating and drinking inside the gym. Diamond stands on Pearl's shoulders in order to watch the battle through the window. Meanwhile, Platinum has defeated all of the trainers and is starting her battle with Roark. Roark starts the match using his Cranidos's Shock Wave attack. Roark substitutes Cranidos for Onix, while Platinum substitutes Piplup for Ponyta. Onix uses Double-Edge and Stealth Rock. Platinum is forced to substitute Piplup back in, who instantly uses Water Gun to force Onix out of the battle. Roark is sure that he has won and has Cranidos use Double Team to prevent Piplup from hitting it. Seeing this, Diamond and Pearl start their comedy routine, giving Platinum a hint to confuse Cranidos. Roark has Cranidos use Zen Headbutt, but Piplup uses Water Pulse and confuses Cranidos. Cranidos knocks itself out, making Platinum the winner. Roark gives Platinum the Coal Badge, and Piplup regains it's confidence. Afterwards, Pearl mentions his father.