Having had a busy time at the Lumiose Gym after parting ways with Ash, Clemont has taken a day off for a fishing competition. Bonnie, looking bored, sullenly states that nothing is being caught. Clemont in response then brings out his new invention, an electronic fishing rod which does everything itself. Cilan beside them then intervenes, retorting that such a rod is the worst type of rod. As a fishing Connoisseur, Cilan, in his usual manner, explains the thrill of fishing which Clemont's device cannot emulate. Clemont argues that he would be able to make a device which captures this thrill of fishing, though Cilan remains unimpressed. Cilan then introduces himself, but as he finishes, Clemont's rod begins to shake. Bonnie grabs the rod quickly and tries to pull, but Cilan notes that it is better to stay still. The fishing lure the pulls downward, at which he then tells Bonnie to pull. Bonnie begins to pull, and with difficulty, manages to reel in a Clawitzer. Clawitzer begins to attack Bonnie, and Cilan responds by taking out his Stunfisk and commanding Mud Bomb. Clawitzer falls back into the river and runs away to Bonnie's disappointment.
The competition then ends and the three walk into the city. Later, Bonnie asks what Cilan will do next, and he reveals that he was heading to Prism Tower as he is a tower Connoisseur. Bonnie reveals that her brother is the Lumiose Gym Leader, and the pair then introduce themselves. In turn, Cilan also introduces himself as the Striaton Gym Leader. Bonnie, now excited leads the way, but Cilan asks whether they could take the subway.
In the subway, Cilan marvels over the ATO (automatic train operation) system. As a subway Connoisseur, he then introduces them to the experimental Super Multi train. The doors of the Super Multi train then open, and Bonnie runs in. However, the doors close right after her, and the train runs off without Clemont or Cilan on board. The two then run to the control room, where the workers state that the ATO has malfunctioned and that all trains are going out of control. Recognizing Clemont as the one who had restored the Kalos Power Plant, the workers let Clemont deal with the issue. Clemont soon finds that there was a problem with the system's microprocessor which had been unresponsive, and quickly the issue is resolved.
However, one train continues to move – the Super Multi train Bonnie is on. Fortunately, as a subway Connoisseur, Cilan knows all the controls within the train. He tells Cilan to use the train's communication system to let Bonnie know to move to the train's operator room. Bonnie, happy to hear her brother's voice follows as he commands, and with Clemont's guidance, opens the door to the operator room with Dedenne's Nuzzle. Cilan then takes over and asks Bonnie to follow, however, the train fails to stop due to a problem with the train itself. After reconsidering his options, Cilan then asks Bonnie to slowly pull a lever towards her, and this time, the train successfully halts. Relieved, Clemont is eager to go to Bonnie, but the subway workers note that the safety of the subway system must be checked first. Cilan then remembers that there is rail inspection cart which they can use to retrieve Bonnie instead.
In the cart, Cilan leads the way, with Clemont using his Aipom Arm to switch tracks. But as Clemont and Cilan are approaching, Bonnie hears a noise rattling the train from above. Cilan notices a hole in the wall of the tunnel, and suddenly the train begins to glow with electricity. The train then begins to move, with Cilan and Clemont following on their cart. When Cilan informs Clemont that the track is a dead-end, Clemont momentarily panics, but they both remember instances of Ash bravely saving Pikachu, and regain confidence, knowing that anything can be overcome with the help of friends. After deep thinking, Clemont thinks of a plan using Cilan's fishing rod and Clemont's electronic lure. Cilan orders Bonnie to open the emergency door of the train. Clemont asks Bonnie to lean forward, and Cilan casts his fishing rod which latches onto the back of Bonnie's shirt. Cilan reels Bonnie in and Clemont uses his Aipom Arm to bring Bonnie to safety, just before the runaway train crashes.
Cilan sighs in relief but wonders what would have caused the train to run away. Cilan then claims he is a detective Connoisseur and identifies the cause as an Eelektross. Cilan then guesses that the Eelektross was probably unable get out after having come in via a sewage pipe. Eelektross's Ion Deluge caused the system to malfunction, and then it rode on top of the train, causing it to run away.
At that moment, Eelektross cries out and shoots another Ion Deluge. Clemont calls out Chespin and orders it to use Pin Missile. This weakens Eelektross, but it quickly retaliates with Crush Claw. Cilan then calls out Pansage, and both Pansage and Chespin use Vine Whip. Eelektross again curls up in anguish. Noticing this, Cilan proposes that the Eelektross is affected from overcharge after becoming lost and frustrated in the subway. Cilan then states that Dedenne's gentle Nuzzle is what is needed to solve this. Dedenne uses Nuzzle on Eelektross, making Eelektross feel instantly better. They then lead Eelektross out of the subway so that it could return to its natural habitat.
Clemont brings an overjoyed Cilan to the Prism Tower. Cilan compliments Clemont for his fishing rod idea, something that he had not tasted before. Clemont then states that he thought of his greatest friend. In surprise, Cilan says he also thought of a friend who never gives up. Clemont then replies that he would like to meet that friend of his, which Cilan then responds by saying that he would definitely meet him one day. Cilan then leaves Clemont and Bonnie for the Tower of Mastery.