A Trip Down Memory Train! (追憶のトレイン！シトロンとホルビー！！ The Memory Train! Clemont and Bunnelby!!) is the 40th episode of Pokémon the Series: XY Kalos Quest.
As the heroes travel on the road, they fall into a hole. While nobody got harmed, the heroes are seen by Team Rocket, who dug this hole. Team Rocket cheers about their success, as they anticipate their foes to hand Pikachu over. Pikachu uses Thunderbolt, but Meowth releases a net, which absorbs electricity. Clemont sends Bunnelby, whose Mud Shot destroys the net, allowing Pikachu to blast Team Rocket off with Thunderbolt. The heroes cheer, but a crack on the bottom of the hole widens, causing them all to fall deeper in. The heroes fall into a coal mine, which is abandoned. Seeing the tracks, they decide to follow the trail to get out. Bonnie reminds Clemont something like this happened to them some time ago, when they met Bunnelby. Ash and Serena would like to know the story, so Clemont decides to tell them.
After being booted out of the Gym by Clembot, Clemont tried to find various ways to go back into the Gym. He became hungry, but Bonnie came with an apple, which was the only piece of food they had at home. However, the apple was stolen by Bunnelby, who ran off, being followed by Bonnie and Clemont. Ash and Serena are surprised, as they find quite hard to believe Bunnelby being like that. Clemont and Bonnie lost Bunnelby, but soon found it beyond a ramp. Clemont and Bonnie jumped, but fell into the hole, beyond the pit. Clemont and Bonnie fell on the tracks in the Lumiose subway, which was inactive for years. Clemont found the map and pointed a route he and Bonnie could take to come out of the subway. Clemont and Bonnie soon arrived to the abandoned station. Bonnie helped Clemont get onto the platform, but they found Bunnelby entering one of the trains.
Bonnie and Clemont watched as Bunnelby split the pieces of the apple to share it with its friends: Trubbish, Delcatty, Skitty, Patrat and Zigzagoon. Bonnie wondered why are they living here, so Clemont reminded her Pokémon need a safe place to live; that was a good place as a shelter for rain and extreme temperatures. Trouble arose, as a Diggersby kicked Bunnelby out and scared off its friends. Diggersby ate all the pieces of the apple and attacked with Mud Shot, negating Bunnelby's Mud Shot and hitting it. Bunnelby used Double Slap, but was attacked by Diggersby's Hammer Arm. Bunnelby dug out a hole and attacked Diggersby, who repelled the attack with Super Fang. Bunnelby circled Diggersby with Double Team, but was damaged by Double Kick. Diggersby used Mud Shot, but Clemont took Bunnelby away safe before getting hit. Diggersby, however, chased them all off with Mud Shot. Serena considers this a bad situation, but Bonnie replies they must not rush into the story.
Bunnelby was badly injured and Clemont, despite not knowing how to treat it, was encouraged by Bonnie to heal it. Clemont took out a potion, explained Bunnelby's friends he will only treat its wounds. Clemont sprayed the potion and bandaged Bunnelby. Bunnelby felt better, but wanted to defeat Diggersby. Clemont reminds Bunnelby that Diggersby is too strong, but did not mean it is impossible to defeat Diggersby. Clemont advised Bunnelby it should lean on defense with Dig and Double Team, then take out Diggersby by using its own strength. Bunnelby did not understand very well, so Bonnie and Clemont make a small play. Bonnie, as Diggersby, fights Clemont, as Bunnelby. Diggersby used Hammer Arm, but Bunnelby dodged, allowing Clemont to show Bunnelby the strategy. Diggersby used Super Fang, but Bunnelby used Double Team. Diggersby attacked all the illusions. Clemont told Bunnelby to use its ears for defensive measures, so Bunnelby pulled out a rock, showing it can win.
Clemont, Bonnie and Bunnelby's friends watched Bunnelby battle Diggersby. Diggersby used Hammer Arm, but missed, due to Bunnelby's Dig, causing it to be bashed onto a pillar. Diggersby used Mud Shot, but Bunnelby dug out a hole and came out before Diggersby attacked it, through the hole, with Mud Shot. Diggersby used Super Fang, but was countered by a rock Bunnelby pulled out. Diggersby used Double Kick, but was negated by Bunnelby's ears, and was slammed off by Bunnelby's Double Slap. They came and saw Diggersby negating Bunnelby's handshake and running away, into the tunnels. Bonnie noticed Clemont and Bunnelby made a good combo, to which they both smiled. The underground started shaking, for the demolition might've been in progress. The Pokémon didn't want to leave, as that was their home, but Clemont thought they may just move the train elsewhere. Bonnie asked Clemont could he actually do that, to which Clemont's eyeglasses flashed. Clemont connected the train's engine to the threadmill, which generated electricity. A rock fell down, blocking their path, but Diggersby arrived and removed the rock with its ears.
Bunnelby came and shaked ears with Diggersby, for Diggersby also wanted to move away. After the reconciliation, the Pokémon, along with Bonnie, moved on the threadmill. Clemont activated the train, which started moving, due to electricity powered by the threadmill. Clemont studied the map and found the lever to change tracks is outside the moving train. Bunnelby used Mud Shot, activating the lever, causing the train to move into the right direction. Despite Bonnie's exhaustion, the train came out of the subway, to the end of the tracks. Clemont explained that was the place where the construction is not planned, plus they got the berries growing around as food. Clemont watched Bunnelby a bit before departing with Bonnie, bidding the Pokémon farewell. Bunnelby was sad, but its friends, including Diggersby, encouraged Bunnelby to go with Clemont. Bunnelby cried, but accepted the offer and went to Clemont. Clemont and Bonnie turned around and saw Bunnelby is willing to go with Clemont. Bunnelby confirmed Clemont's question and became his partner.
Serena and Ash consider this a nice story, how Clemont got his first non-electric type Pokémon. Clemont is also glad, for with Bunnelby's help, he got the Gym back from Clembot. The heroes arrive at a dead end, so Bunnelby uses Dig, revealing the exit. After getting out of the mine, Bonnie tells that was not the end of the story. Just when Clemont threw the Poké Ball, Bunnelby allowed itself to be captured. Clemont sent Bunnelby out and hugged it, crying, for he will be with Bunnelby forever, since Clemont was very happy when Bunnelby came back to them. Bonnie claims that is the "real" end of the story while Clemont claims Bonnie was exaggerating, but Bunnelby comes on Clemont's shoulder, still glad Bunnelby is traveling with its master.
- "Pokémon Quiz:" Diggersby (JP)
- "Who's that Pokémon?:" Trubbish (US)
- This episode aired in Canada earlier than the US.