The heroes returned to Mt. Coronet. Though a bit foggy, they soon come to a river. They spot some sad Shellos, whose skin is blue, as opposed to Zoey's Shellos, who is pink. They see a pink Shellos is in the river, almost to be swept away. Piplup dives in to save it. He gets the Shellos, while the gang lower a branch and Pikachu lowers his tail, so they are saved. They see a Nurse Joy coming, who is relieved to see Shellos saved. Brock is relieved to see her and Croagunk is relieved to attack him and drag him away. Nurse Joy think it is strange to see a Shellos coming from western part of the mountain (the pink variant) on the east (with the blue Shellos).
Nurse Joy explains when Mt. Coronet was raising up, the Shellos separated and adapted their color, but recently they began to be lost and come to the other side of the mountain. Nurse Joy treats it back at the Center and Shellos is fine. Ash offers to get it back where it belongs, which Nurse Joy approves. Looker arrived and sees another Shellos got lost. Looker goes away quickly, so the gang goes to get the Shellos back. Meanwhile, Team Galactic, per Cyrus' orders, has been sent with Saturn's command to search for the Spear Pillar. Charon, the scientist explaines that with time they will find the object beneath Mt. Coronet.
Team Rocket watch as they search. Jessie points at a case, in which she presumes is treasure stored inside, so plan to get it. Looker has found the hideout, while Piplup carries the Shellos on his head to its friends. They see many caves are in the area and Dawn warns Piplup to be safe. Piplup and Shellos peek through a hole, but fall down. Ash, Brock and Dawn come to see what happened, but fall down as well. Looker searches and sees footprints and determines the tunnel was recently dug out. Though the gang is safe, they see they cannot get out.
Though Saturn is annoyed by the fact they saw more ruins than the Gateway to Spear Pillar, so Charon explains that the people around believe in Space-Time Legend. Looker sees Team Galactic is in the ruins. The heroes try to escape the cave, but see they are not the only ones, as they see many footprints. Brock sees another tunnel, which is not formed naturally, in which Shellos goes to. Shellos goes further and Brock realizes someone dug out the tunnel. Ash proposes to ask the people to get out, so they go further into the tunnel. They see some light at the end and coming in, they encounter Team Galactic.
Saturn commands his recruits to surround them. Team Rocket and Looker watch this event. A moment later, they are all tied up. Charon now sees the children who caused the rubble, but Saturn commands him to get back to work. Though somewhat saddened by this event, Team Rocket still have their eyes on the case. Shellos begins to cry, so a recruit goes to shut it, while Saturn sees Team Rocket are hiding. The recruit comes and intimidates it, but he whispers he will return it. He turns to the gang and unties them, pretending to fasten the ropes, while telling them that Team Galactic are searching for ruins.
Saturn asks the recruit who he is, so the recruit responds he is sent by the Team Galactic HQ to assist them, but does not know what they are doing here. Charon explaines they are looking for the Gateway to Spear Pillar inside the mountain, then they will use the key (which was used on occasions) to unlock it. Saturn warns Charon the key needs to be safe, though Charon replies he cannot care else about it, nor their goal or Dialga and Palkia. Team Rocket see it is not an ordinary key, but will try to grab it.
Charon orders the recruit to get back to work. The recruit jumps and cuts the ropes, and unsidguises himself, who is really Looker, a member of International Police. Shellos goes away, so the gang goes to get it. The Team Galactic recruits go to get Looker. Team Rocket go as well; Jessie sends Seviper, who uses Haze to dim their vision and when the smoke clears, the key is in possession of Team Rocket. Team Rocket begin their chant, but are interrupted by Charon, who demands the key back. Since they do not want to do it, Team Rocket are soon surrounded by Golbat.
The heroes calm the Shellos down and witness Looker fighting Team Galactic members. Some recruits have a signal, so Saturn sends Toxicroak, who crashes through the wall using Rock Smash. Soon, everyone sees the ruin was behind the cave wall. Charon confirms that it is the Gateway to Spear Pillar, so the Golbat get the case Team Rocket stole. Toxicroak's Dark Pulse manages to blast them off. Charon demands the key to open the Gateway and show the Spear Pillar, but the key lies still in the case. Charon explaines to Saturn this is not the Gateway, but an another ruin. Saturn tells the recruits to retreat.
The Golbat surround Looker, so Pikachu uses Thunderbolt and Piplup BubbleBeam on Team Galactic, but the Golbat use Protect and they manage to get away. The walls crack and the cave begins to be filled with water,as Toxicroak crashed the wall. Looker gets a floatable boat out of his jacket and soon they all get out. Charon now knows there are ruins on Mt. Coronet, they only need to be searched out. The gang thanks Looker for the help and are surprised by the fact he is a member of International Police. Looker tells them he will go back to the HQ, while the heroes promised to take back Shellos, which they will. Looker sees on the map they are on the western side, so Shellos' home shouldn't be far.
Brock sees the mountain water plugged the entrances, due to the sediment, meaning the Shellos won't get lost, while they see Shellos came back to its friends.
- Shellos (East Sea)
- This episode, which features Team Galactic, also marks the 100th episode since they made their debut.
- Brock narrates the next episode's preview.
- Music from Lucario and the Mystery of Mew, and Pokémon Ranger and the Temple of the Sea are used in this episode.
- This is the final episode to use a 3:2 aspect ratio for the episode's beginning in the high-definition feed.
- This episode shows Looker hitting a Galactic Grunt, despite other episodes with less violent scenes being cut.
- This is one of the few episodes to retain all of its Japanese background music and use no dub created music.
- There are a few scenes where Ash's jacket is longer than it should be.
- In one scene, a part of Dawn's vest was colored the same as her skin.
- At the end of the episode, during the "To Be Continued..." scene, Piplup's feet are blue.