Episode 164
Ash and friends have finally arrived on Metallica Island, the location of the Battle Palace. Before challenging the Frontier Brain, Ash does a little training hoping to boost Sceptile's confidence. However, Sceptile still can’t muster the strength needed to use attacks and runs into the woods frustrated. Ash and Pikachu quickly run after Sceptile, but once the get on the woods, they are attacked but a swarm of Beedrill and are knocked into the river! Ash manages to save Sceptile, but Pikachu is swept away! Ash and Sceptile manage to get of the river and take a rest for the night, and Pikachu also manages to get out of the river. An old man finds Pikachu and helps to heal him. When Scott appears at the Pokémon Center, he reveals to the others that this is the time of year when the Kakuna evolve and Beedrill will attack anything to protect them! Can Ash manage to find Pikachu, boost Sceptile’s confidence, and get out of the woods without being stung?
Aired 09/02/2006EP 164 - Episode 164

Pokémon the Series: Ruby and Sapphire
After participating in the Johto League, Ash decides to begin anew in yet another journey; this time by himself and Pikachu, in the land of Hoenn. Though he isn't alone for long, as 10-year-old May (who dislikes Pokemon, but just wants to come along to see the world) travels with him after Pikachu destroys her bicycle. Ash also meets up with his old companion, Brock, and May's younger brother, Max. Together, they travel along in Hoenn, battling Gym Leaders, entering Contests, and other events on the way to the Hoenn League.
(Source: Anime News Network)