Ash contacts Professor Oak who tells them about a hotel in the city that serves a delicious dessert. They head to the hotel, but it is closed. As they turn to leave the door mysteriously opens. They then head inside where they are attacked by a Rotom.
While awaiting the return of the Canalave Gym Leader, Ash decides to train. Dawn also decides to begin training her newly evolved Piloswine for its contest debut. However, Piloswine begins to ignore Dawn. Trying to reconnect with it, Dawn enrolls in a "Pokémon Friendship School".
Roark, the Oreburgh Gym Leader, and son of Byron, the Canalave Gym Leader, is visiting his father. The two of them, both users of Fossil Pokémon, are having an argument about who likes them more; and they end up battling. Meanwhile, Ash has returned to the Canalave Gym for a Gym Battle after hearing that Byron is back.
Ash finally gets to battle the Canalave City Gym Leader, Byron. In the first round Byron chooses his Bronzor, while Ash uses Chimchar. Ash tries to use Chimchar's type-advantage to score an early victory, but this begins to prove ineffective when he learns that Byron has a defensive style of battling.
Ash and friends are having lunch when all of a sudden a Luxio comes along and steals all of their food. They follow it into the sewers where they discover a Wailmer that is trapped in the sewer and can't make it back to the ocean.
Everyone is getting prepared to leave Canalave City to head to Dawn's next contest. Before they leave, Ash calls Barry to tell him of his win at the Canalave Gym. Barry is at Iron Island, and something is currently wrong with his Empoleon. Ash, Dawn, and Brock head to Iron Island to see him, but all of the steel pokémon are going crazy. A man named Riley appears and helps them, and they decide to find the source of the problem.
Ash, Dawn, and Brock, along with their new friend Riley search for the source of the mysterious waves affecting the Steel Pokémon, and find Team Galactic. What is Team Galactic's plan, and what do they want with the ruins on Iron Island?
Ash and friends decide to take a boat to the location of the next contest. On the ride Team Rocket appear and steal Pikachu and Piplup. They manage to escape but they wind up on a deserted island. Will they be able to make it back to their trainers?
Ash and friends arrive in the town where Dawn will enter her next Pokémon Contest. They find out that a lot of people have come to the town in order to see the legendary Pokémon Phione, who lives in the surrounding sea. Legend has it that anyone who sees Phione will have good luck, so Dawn decides to try and catch a glimpse of it.
Dawn is getting ready to participate in her next contest. She meets a girl with a Gabite who is not so friendly. She believes that Dawn's victory in the Wallace Cup was pure luck and is determined to defeat Dawn. Dawn is now determined to defeat her and prove that her win was not just luck.
Ash and friends arrive in a town where an Officer Jenny and her Chatot are working hard to find Team Rocket and arrest them. Jenny wants Ash and friends to help.
Ash and friends are lost in a blizzard when they run into a Froslass. Froslass leads the trainers to a small lodge, where it provides them with warm soup and a bath. But is it as friendly as it seems?
After yet another failed attempt to steal Ash's Pikachu, Team Rocket wind up at a Ramen shop. Jessie and James are surprised when they discover that the shop owner was one of their underclassmen from their days at the Team Rocket training facility.
On the way to Snowpoint City, Ash and friends stop in a town where a PokéRinger competition is to be held. Ash is eager to participate in the contest with Staravia. However, he soon finds out that Paul is also entering with his Honchkrow.
On the way to the next town, Ash and friends decide to stop and take a break. Dawn heads to a river to fill up her canteen, but is attacked by a wild Aggron and falls into the river. She manages to get out of the river far down stream, and is now lost from Ash and Brock. Aggron returns and after calling out Mamoswine, it is badly hurt. Now, Dawn must take care of Mamoswine by herself, and hide from Team Rocket and Aggron at the same time.
A Snover plays tricks on the group but provides some berries but Team Rocket soon strikes.
Piplup starts to glow indicating it is about to evolve but Piplup doesn't seem happy about it.
Dawn hopes to win her final ribbon but her old rival Kenny is taking part.
Ash, Dawn and Barry take part in a Ping Pong Tournament, Ambipom seems very keen.
A young trainer thinks that Buneary is cute but offends Piplup by saying the opposite.
Arriving in Snowpoint City, their friend Zoe shows them around and introduces them to Candice, the gym leader.
Ash takes on Candice using Grotle, Staraptor, Gliscor and Chimchar.
Paul arrives to challenge Candice who can't battle as Brandon arrives.
Hunter J attacks the Snowpoint Temple in the hope to get Regigigas for her client.
Travelling on the Ampharos train, Ash, Dawn and Brock encounter Looker as the train mysteriously comes to a stop.
Ash arrives with Brock and Dawn at Lake Acuity to have a full 6-on-6 battle with Paul.
The full battle continues with Grotle and Weavile down but who will win?
His massive defeat against Paul has left Ash feeling less confident as Dawn tries to cheer him up.
Grass type Pokémon are draining the energy of the groups Pokémon and the gang investigate.
Dawn's favorite television show, Pokémon Hustle, is searching for actors near their current locations, and Dawn decides to try out for the show. Ash and Brock decide to try out, as well.
The group finds a Shellos but for some reason it is on the wrong side and investigate.
Piplup falls in love with a Marill but a love triangle is created when an Elekid falls for the same Marill.
Dawn returns home where the Twinleaf Festival takes place.
As the Twinleaf Town Festival continues, Ash and friends are surprised when they find that one of the upcoming Pokémon courses is to be hosted by none other than Professor Oak. Trouble starts brewing, however, when James brings back an old plan: to disguise himself as the professor.
Barry arrives at the Festival but along with Dawn and Ash encounter a Natu and have a strange experience.
Barry's father is a Frontier Brain and the winner of a tournament can have a battle with him.
Team Rocket have a new base and have the gang trapped but a Togepi is causing trouble.
Dawn has run an egg from Lyra but Team Rocket soon get their hands on it.
The two Johto trainers decide to join Ash, Dawn, and Brock on their journey. While on the way to Dawn's next contest, the group stops near the Valley Windworks for Dawn to do some training. When Marill goes missing, the group heads into the windworks to find it, but once inside they are attacked by wild Pokémon and become trapped. Will they be able to escape the building?
A wild Gible is causing trainers trouble as Ash and Khoury both attempt to catch it.
Dawn enters the Lilypad Contest hoping to win her final ribbon but James enters covering for an ill Jessie.
As Lyra and Khoury prepare to return to Johto, they decide to have a tag battle.
Trying to find a Dusk Stone causes sibling rivalry as they try to evolve their Pokémon.
A strange force is making electric and water types fall in love with each other including Pikachu and Piplup.
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.
As Team Galactic's plan nears the end, Hunter J is hired to capture the Lake Guardians.
Ash, Brock and Dawn are held hostage and Cyrus prepares to summon Dialga and Palkia.
Monferno uncovers a treasure chest and James is horrified as he knows what it contains.
Gliscor has trouble flying on the wind and a master offers his help.
Knowing that the next contest is going to be a double performance, Dawn begins training Mamoswine and Cyndaquil. Zoey arrives and decides to help Dawn with her training.
Wilma can teach Dragon types to learn Draco Meteor as a Gible struggles to master it.
Ash and friends continue on their way to the next town when they notice that the Gible they helped has been following them. Ash decides to try and catch it, but Barry shows up and wants to catch it too. Now the two trainers race to capture it first.