Still on their way to Mossdeep City, the group has now stopped off at a beach. Brock flips out over the girls in swimsuits while the others comment on the beautiful beach. Suddenly, they notice a shape in the water, and a weird, laughing seaweed creature emerges, scaring the group. Ash wonders if it’s a Pokemon, but Brock doesn’t think so. Then the “creature” drops a sack on the ground, and removes its weeds and mask to reveal that it’s actually a man in a wetsuit. He introduces himself as Soya and produces a necklace made of Green Shards from his sack. He explains that this is what he does for a living, diving in search of treasure such as this, and takes the group back to his shop. There we see many shells and such from various Pokemon for sale. Soya’s wife, Erimo, examines the necklace as Soya tells her about what he found underwater.

After the couple explain more about their business and the various things they’ve dealt in, Soya tells of his plans to look for a long-lost treasure from a sunken pirate ship. We see a flashback of the ship sinking in a whirlpool during a storm, as the crew struggles in the water and escapes on lifeboats. Soya goes on to say that he believes there’s a connection between the local Relicanth and the treasure, because he found that necklace hooked onto a Relicanth. Ash then looks up Relicanth in the Pokedex, and the group speculates for a bit. Soya expresses his determination to find the Relicanth again and hopes they’ll lead him to the treasure, and Ash says they would love to go with him.

Outside in the bushes, Team Rocket has overheard this whole conversation. Jessie and James want the treasure for themselves, but Meowth wants to give it to the Boss, as usual. He has a vision of Giovanni asleep in a super-rich-looking bedroom studded with gold and precious metals everywhere, and of course waking up to say he owes it all to Jessie, James, and Meowth. They cheer at the thought, and determine to get the treasure.

Out on the ocean, Erimo mans their boat while the others prepare to dive down in Soya’s submarine. After preliminary checks, it’s full speed ahead, and the diving mission is on. As the sub dives into the darker, deeper parts of the ocean, Soya turns on its headlights, illuminating some Wailmer, Huntail, and other Pokemon. Max spots a group of Chinchou, and the others talk about the Pokemon that live this deep in the ocean. Finally, a Relicanth appears on Soya’s monitor and radar. Just then, the ship shakes violently, and Erimo radioes down to check on them. Another monitor shows the cause of the disturbance—a giant Magikarp that is ramming the sub! Ash recognizes it as Team Rocket’s Magikarp sub, and warns Soya about them, while Erimo listens worriedly from above.

Inside Team Rocket’s sub, they peddle along doggedly, and James sends out Chimecho to give them added motivation. Meowth hits a button that fires two torpedoes at Soya’s sub. They connect, and the sub shakes again, causing damage to several instruments. TR pulls up alongside them and taunts via radio that they’ll get the treasure first. Everyone is ok, so Soya radioes their situation to Erimo and says they’re going after Team Rocket and continuing their mission. Ahead, TR are following a Relicanth they think might lead them to the treasure, when they notice their sub has started leaking badly. James and Meowth are worried, but Jessie wants to push ahead. That’s when the holes get bigger and water starts gushing in. TR loses control and is helpless as their sub is pushed along by a current. Soya and the others have caught up now and again have the Relicanth in their sights. The sub starts experiencing turbulence again; it seems the currents this deep are pretty rough. Still, Soya suspects that they must be close, and follows the Relicanth into a small tunnel. Above, Erimo worriedly tries to raise them on the radio, but communication is now knocked out due to their location. Soya skillfully maneuvers the sub through the small tunnel, but the rough current knocks them against the sides several times. Soya finally loses control, and everyone hangs on and braces themselves.

The screen goes black, and an unconscious Ash is awoken by Soya. Everyone else appears to have been knocked out as well, but they awake with no harm done. All the sub’s interior emergency red lights are on now. The group looks out the window and discovers they’ve made it to shore in an underwater cave containing the pirate ship Soya had told them about! Soya rushes off to explore the ship while the others discuss their situation. Presently, a group of Relicanth emerge from the hull of the ship, and the humans admire them. Soya suddenly emerges, having found a treasure chest. Just as he is about to open it, they hear a voice from the water. It’s the radio from TR’s Magikarp sub, and they emerge and say their motto. Meowth hits a button that sends a rope out from the mouth of their sub, with a plunger at the end. It takes the treasure chest back into the sub, as Soya rushes forward in anger. Meowth stops him by hitting another button that sends out two more torpedoes. Soya and the others duck as the torpedoes fly over them and strike the wrecked pirate ship, disturbing and endangering the Relicanth. TR gloat over their success, but notice that they are now surrounded by a bunch of angry Relicanth. TR yells at them, but to no avail. Jessie snatches the remote from Meowth and sends out two more torpedoes that fly towards the Relicanth. Ash quickly sends out Corphish, who destroys the torpedoes with Bubblebeam. TR takes the opportunity to make their escape, and they even make sure they can’t be followed. Meowth hits another button that sends two rockets out from the back of their sub, causing a cave-in at the tunnel entrance. Soya, Ash, and the others are worried, but then they notice the Relicanth are all starting to swim in one direction. One of them pauses to call out to the humans, who realize the Relicanth must know of another way out. They get back in the sub and follow the Relicanth to another underwater tunnel, but the current looks rough in this one too. Soya assures them that they’ll make it through.

Meanwhile, on the surface, Erimo is still desperately trying to regain radio contact with the group. Finally, the speaker crackles to life. Soya explains what happened and says the Relicanth are leading them back up. Back on board the boat, Ash & co thank the Relicanth, while Erimo scolds Soya briefly. But she has picked up TR on their radar, so they can still try to reclaim the treasure.

Some distance away, TR has also surfaced, and gloat over their victory, but that’s when Ash & co catch up with them, accompanied by the group of Relicanth. From the boat, May sends out Bulbasaur to grab the treasure chest with its vines. TR won’t let it get away that easily, and grab the chest as well. Jessie sends out Seviper, who hits Bulbasaur with Poison Tail, breaking its hold on the chest and sending it flying. Brock sends out Mudkip, who attacks TR with Water Gun as the Relicanth join in with Hydro Pump. Bulbasaur grabs the chest again with its vines and gives it to Soya. Finally, a Thunder from Pikachu blasts off the Rockets.

Soya can now finally open the treasure chest. Inside, everyone is surprised to only find more Green Shards. Soya is disappointed, but Erimo says she can make some great jewelry out of them, much to May’s delight. Erimo even offers to make something out of them for May, who happily thanks her. Soya thanks the Relicanth for everything, and expresses determination to continue his treasure-hunting adventures. As the sun sets, it’s now time for Ash and friends to continue on towards Mossdeep City.

Thanks To Geodude For Writing this for us