Lost at the Stamp Rally! (Japanese: サトシ、デントVSサブウェイマスター！ Hepburn: Ash and Cilan VS the Subway Masters!) is the 3rd episode of Pokémon: BW Rival Destinies.
After defeating Elesa and earning himself the Bolt Badge, Ash and co. decide to pay a visit to Ingo and Emmet. Cilan starts to collect 60 stamps at the stamp rally to battle Ingo and Emmet. Meanwhile, Ash and Iris find an Axew that is lost all the way here in the Nimbasa City amusement park. Somehow, the trainer name Erina bump into Cilan seeking questions on how to get to the amusement park looking for her friend (which means her Axew). Will they be able to find her trainer and each other? And do Ash and Cilan have what it takes to beat Ingo and Emmet?
Ash and Iris speed up to catch up with Cilan, who goes to the Subway. He explains there is a rally of stamp collecting. Even if it is the final day, Cilan is still up to the challenge to collect all 60 stamps and once he obtains them all, he can battle Ingo or Emmet. Ash also wants to participate, but promised Iris to go sightseeing Nimbasa City, making Cilan displeased. Later, Ash and Iris come out of the train and see a commercial of football clubs, Team Darmanitan and Gurdurr 11, the latter being favorite for Iris, for they have always been training in the Village of Dragons. They go inside the stadium, while Cilan is determined to collect all the stamps.
Eventually, Iris is pleased Gurdurr 11 won the match, so she and Ash play tennis for a while. As Cilan collects the stamps, Iris and Ash watch a musical. Oshawott comes out, admiring the play. Ash tries to pull him, but the actor, Gothitelle, uses Telekinesis, then the Pokémon come around Ash, Pikachu and Oshawott. A moment later they wear performer suits and entertain the audience. Once they get out, Iris notices the Ferris Wheel and runs off. Ash tries to find her and encounters a female Axew. Iris comes back with ice cream and gives it to Ash. When she sees the female Axew, she wonders if Axew is lost. Iris does not want to leave the female Axew, so she and Ash go to search for her trainer. Cilan is nearly finished with collecting stamps and is approached by a girl, who wants to know where to go to the amusement park. Upon telling the directions, the girl leaves, so Cilan focuses on obtaining the last stamps.
As Ash and Iris wait for the train, the female Axew sees someone and runs off. Ash and Iris go inside to see who that is. However, the train moves, so they help an old lady get up (for she fell down), while Iris sends Emolga to find the female Axew. Cilan is close to finishing the stamp collecting and notices the girl again, her name being Erina. Erina admits she was going to the amusement park with her friend, but they got separated and she got lost. Cilan promises he will reunite Erina with her friend, being a metro Connoisseur. The female Axew jumps on a girl, but is surprised, as that is not her trainer. As the train passes by, Erina notices her Axew. Axew gets wrapped by a trainer's Swadloon. Emolga notices this and electrocutes everyone, including Ash and Iris.
Later, Ash, Iris and the Pokémon apologize to the train conductor, who warns them to be more careful next time. Iris thinks they should go to the amusement park, for they won't gain much by standing around. To let Axew's trainer know they've been here, Iris has Axew leave a footprint on the paper and she places it on the wall. Soon after, Cilan and Erina come and see Axew's footprint on the paper, so they see it should be at the Ferris Wheel. They go inside a train, but Cilan is shocked, as they are going in the wrong direction. Ash and Iris try to find the trainer, but have no luck. Still, they promise they won't give up. Erina apologizes, for they are in the wrong direction because of her, but Cilan thinks he is guilty for mixing the directions. He sees the map of the Underground and realizing they are close to the center, Cilan has an idea.
While Ash and Iris wait, a train conductor comes, telling them to go to the center of the Underground. Ash and Iris take the train and wait. Axew sees her trainer, Erina, and runs to her. Cilan is pleased the case is solved, but Ash and Iris do not know how he found them. Cilan replies with the help of the Subway Bosses, they managed to track them and bring them to this spot. Iris reminds Cilan of his stamp collecting, making him upset he has not much time. However, the deadline passed, making Cilan heartbroken he cannot take the challenge. However, Erina gives him a paper with Axew stamp, during the time she was looking for Axew. Cilan accepts that, so Ingo and Emmet accept Cilan's challenge, turning it into a Tag Battle with Ash as well. They arrive in a train cart, which turns into a battlefield, making Cilan pleased.
The Subway Bosses send Chandelure and Eelektross, while Cilan and Ash their Pansage and Tepig. Tepig uses Flamethrower on Eelektross and Pansage Bullet Seed on Chandelure. Tepig uses Flame Charge on Eelektross, hitting it, while Pansage uses Solarbeam, but misses due to Chandelure's Smog. Chandelure uses Will O' Wisp on Pansage, but gets countered by Tepig's Flamethrower. Eelektross uses Acid on Pansage and Tepig. Cilan admits the Bosses battle the way they run the Subway: with precision. Cilan's Pansage jumps and leaps on the benches and rails, using Bullet Seed on Chandelure and Eelektross, while Tepig uses Flame Charge. The Bosses see Pansage is connecting the lines, while Tepig drives through, like a train system.
Eelektross uses Thunderbolt on the rail, hitting Pansage, who falls down, causing Tepig to fail to use Flame Charge. Chandelure uses Psychic, followed with Eelektross' Thunderbolt, which defeats both Tepig and Pansage. Later, Cilan and Ash thank the Bosses for the battle, learning much from it. The Bosses report the bridge has been fixed, allowing the heroes to continue towards Driftveil City. Erina tells her Axew they could go to the Ferris Wheel. The heroes take it, too, as they see the scenery of Nimbasa City, while Ash hopes to get to the next City and obtain the fifth badge.
- Two football players on the jumbo-tron had uniforms designed like Gurdurr and Darmanitan respectively.
- They were called the "Gurdurr 11" and "Team Darmanitan" respectively.
- In the games, Tennis and Basketball alternated each day of the week in Small Court.
- Professor Oak's Live Caster: Stoutland
- Who's that Pokémon?: Eelektross (Japan), Chandelure (U.S.)
- Emmet and Ingo's official artwork for Pokémon: Black and White can be seen.