Ep 4. The Keystone Pops

Ash, Dawn, and Brock continue on their journey to Hearthome City while encountering many different kinds of Pokémon along the way. In this particular episode, titled "The Keystone Pops," the trio ends up stumbling upon a mysterious group of individuals who are searching for a strange object known as a "keystone."

As they investigate further, Ash and his friends discover that the keystone is an ancient artifact that is said to have the power to unlock the secrets of a certain type of Pokémon. The group soon realizes that they are not the only ones interested in finding the keystone, and they must work quickly to get their hands on it before it falls into the wrong hands.

As they navigate their way through a series of challenges and obstacles, Ash, Dawn, and Brock are forced to use their wits and their Pokémon battling skills to battle against a powerful rival who is also after the treasured keystone. With high stakes and intense battles, "The Keystone Pops" is an exciting and action-packed episode that will keep viewers on the edge of their seats.