Unlocking the Red Chain of Events!
On the way to Sunyshore City, Ash and friends are walking through a grassland and come across Meowth of Team Rocket, who is injured. When they ask him what happened while treating his wounds, Meowth says that he was attacked by Team Galactic in a large building called the Fuego Ironworks. Not only that, Jessie, James, and even Looker of the International Police have been captured. Upon hearing this, Ash and the others decide to head to the Fuego Ironworks to save them.
Aired 05/11/2009EP 150 - Unlocking the Red Chain of Events!

2006
Pokémon the Series: Diamond and Pearl
After defeating Brandon and declining the offer to be a Frontier Brain, Ash sets off to travel through the far away land of Sinnoh. Once he gets there, he meets up with Hikari, a local trainer from the region, and they decide to travel together.