The gang is moving to the Battle Arena. Still, Brock, May and Max are exhausted and want to rest, but Ash still wants to get the second Frontier Symbol. Later, however, Ash is exhausted as well, so they rest. He asks for water, but there is no water left. Brock, May and Ash leave Max with the Pokémon (with only Mudkip coming) to feed. After the search, Mudkip found a river. Meanwhile, Max gives them the food, telling them they need and goes to rest. Pikachu tells the Pokémon which one is first, though all Pokémon want to eat. However, Munchlax ate all the food. Pikachu goes away and Corphish is angry at Munxhlax, even more when it goes to sleep. Corphish uses Bubble Beam, but Munchlax goes to sleep, so the attack hits Squirtle.
Squirtle counter-attacks with Bubble, so Corphish uses Harden. Pikachu tries to wake Max up, while Corphish uses Bubble Beam and Squirtle uses Bubble. With all the trouble, some Geodude begin to be angered and surround them. Phanpy rolls, and so do Geodude, so the other Pokémon run. Max wakes up and sees Corphish knocked out and Munxhlax being thrown away. Pikachu wakes Corphish up and run away from the Geodude. Max sees Munchlax, Pikachu and Corphish are gone, while the others come to him. Ash, Brock and May come, so Max tells him the problem. Brock decides to stay if the Geodude come, while Ash, May and Max take Mudkip to find the other Pokémon.
Meanwhile, there seems a meeting going on - the Geodude complain about the Onix (which must be their leader) about what happened. Team Rocket sees them, so Meowth translates that they had troubles with some Pokémon, including Pikachu, so they know that the gang is nearby. Jessie proposes to talk with the Rock Pokémon and convince them to capture Pikachu and the other Pokémon, as they are their enemy. Team Rocket comes to them, convincing that the gang is planning to capture every Rock Pokémon from Onix's kingdom. They also say they need to capture Pikachu, as their most powerful weapon. Onix yells and soon the Rock Pokémon disappear in a smoke.
Meanwhile, Ash, May and Max search for the missing Pokémon, while Pikachu and Corphish wander. Phanpy finds Squrtile, who is smelling the flowers. Phanpy approaches Squirtle, and Squirtle sees a giant flower. A Beedrill comes out, so Squirtle is taken back and cries. Phanpy stands in its defense and uses Hidden Power to hit Beedrill. Next, Phanpy sees Squirtle smelling the flowers, as well as more Beedrill coming. Phanpy takes Squirtle, who is angry since it cannot smell the flowers, but changes its mind when seeing the Beedrill coming. Pikachu and Corphish wander and encounter Phanpy and Squirtle running. They greet them, but when Phanpy and Squirtle pass, Corphish uses Bubble Beam, when seeing the Beedrill, hitting them. Pikachu uses Thunderbolt to scare the Beedrill and they go away.
Meanwhile, Brock is waiting for the others and is bored. However, the Rock Pokémon arrive and surround him, while Team Rocket drops the cage on him. Corphish, Phanpy, Squirtle and Pikachu see the eaten apples falling, as well as Munchlax eating them. Munchlax falls down, as the ground shakes for the Rock Pokémon to come. When seeing Golems and Gravelers, they run away, with the said Pokémon following them. They spot a log, so Phanpy, Squrtile, Pikachu and Munchlax jump on it, with Corphish pushing the log and losing the Rock Pokémon. However, they hit a stone and fall into water, down the river. Later, they are seen tired, but on the coast. However, the Rock Pokémon surround them and the cage falls, capturing them by Team Rocket. The Pokémon attack the cage, but soon find that the cage is durable and are knocked out, with the Rock Pokémon taking them.
Brock and the Pokémon are taken to Onix. Meanwhile, Ash, May, Max and Mudkip came to a dead end, with Mudkip sensing the Pokémon up there. Ash climbs up and sees Brock and the Pokémon captured. Soon, Ash finds out May, Max and Mudkip are captured as well and are soon taken up where Brock and the Pokémon are. Team Rocket already plans to take the Pokémon for the boss. Brock demands for all to be free, so Team Rocket tells Onix of their hostility. Ash comes and persuades that Team Rocket is the ones lying. Meowth tells Onix he is the bad leader, though Ash tells him he would never hurt a Pokémon, with May and Max telling the same. Meowth tells Onix the gang wants to confuse him, but Ash wants a test to prove himself.
Meowth translates that Onix does not know whom to believe, but wants a battle as a proof. Ash accepts the challenge, as it seems the only way to free his friends. He sends Grovyle to battle. Onix starts with Iron Tail, but Grovyle evades using Quick Attack and tackles Onix, but because it is a Rock type, Onix does not take much damage and attacks Grovyle. Grovyle uses Bullet Seed, hitting Onix, while Onix counters by wrapping Grovyle. However, Grovyle evades and uses Bullet Seed on his head. Grovyle defeats Onix using Leaf Blade. Team Rocket see Onix losing, so they plan to get Pikachu, but since they'd abandon the other Pokémon, they plan to take Onix instead.
Team Rocket appears in a machine, throwing a huge boulder at Onix. Grovyle uses Leaf Blade to stop the boulder and smash it. Onix declares to set the others free, so the Rock Pokémon destroy the cages. Team Rocket launches the cannons, using water to defeat the Rock Pokémon. Team Rocket launches hands to get Pikachu and Onix, as well as a balloon to get away. Still, Onix struggles to resist, with the help of the Rock Pokémon. Mudkip uses Water Gun and Corphish Bubble Beam, destroying the hand which took Pikachu. Squrtile uses Bubble to free Onix. Pikachu uses Thunderbolt and Onix Iron Tail to blast Team Rocket off. Later, the gang are seen to be traveling on the Onix, who helps them to transport them away.
- The dub title is a pun on the educational product Hooked on Phonics.
- This episode is featured on the Volume 20: Onix copy of Pokémon All-Stars.
- Jessie makes a reference to Elvis Presley's song Jailhouse Rock.
- This episode's name is misspelled as "Hooked on Onyx" when it should be "Hooked on Onix".
- When Phanpy saw the Beedrill, one eyes had sclera and the other didn't.