As the Whirl Cup matches continue, Officer Jenny alerts Sea Priestess Maya to a threatening call that the Sea Spirit will be stolen. Maya, however, is unfazed and assures Officer Jenny that the Sea Spirit will be fine as Team Rocket watches from the shadows waiting to snatch the precious item. Meowth was keen to keep selling food, but Jessie reveals that she has planned an infallible aerial attack. With her reassurance, James and Meowth are instantly on board.
Meanwhile, Ash and Misty are ready for their two-on-two Whirl Cup match. Misty first calls out Poliwhirl and Ash sends out Totodile. Ash starts things off by having Totodile use Water Gun, but Poliwhirl dives underwater to evade it. Poliwhirl makes some swift movement through the water and it leaps high into the air to land a direct Bubble attack. Totodile is left dazed, but ducks to avoid Poliwhirl’s Double Slap attack. Totodile retaliates with a Headbutt which sends Poliwhirl backward. Poliwhirl isn't finished yet as it kicks off a pillar and then does a high-speed dive towards Totodile. Ash orders a Water Gun, but Poliwhirl evades and Double Slaps its opponent to claim the round.
Ash recalls his fainted Totodile and sends out Kingler. Misty again commands Poliwhirl to unleash another Bubble, but Kingler dishes out a Crabhammer attack. Its claw strikes the water, and an energy sphere is sent across the arena causing whirlpools to form. The energy hits Poliwhirl, sending it tossing into the whirlpools. Kingler then uses another Crabhammer attack, knocking Poliwhirl out.
After recalling Poliwhirl, Misty then tries to call out Corsola but instead, Psyduck comes out and immediately embarrasses itself and Misty by falling into the water. It nearly drowns before pulling itself onto the platform. Ash, happy about his sudden good fortune, tells Kingler to go up for a Vice Grip attack. Misty tries to command Psyduck, but it's too scared to do anything as Kingler speeds towards it before clamping onto its head. Misty tells Psyduck to try and shake itself loose, but as Psyduck is panicking and flails about helplessly, Misty realizes that a headache is brewing. When Psyduck’s eyes begin to glow with Psychic energy, Ash realizes that he's made a serious tactical error and tells Kingler to throw Psyduck away. Using this to her advantage, however, Misty tells Psyduck to use Confusion. Psyduck summons a surge of psychic energy that sends Kingler crashing right into Ash, knocking them both out and allowing Misty to win the match and claim her first-ever victory against Ash.
Later that evening, Ash contacts Professor Oak to update him on his status in the tournament and also check on Bayleef. Oak is instantly knocked out of the way by Bayleef as she pleads to return. Ash quickly sends off Kingler to the Professor, and when Bayleef returns, she is overwhelmingly happy to be with Ash again. A Trainer approaches Ash and his friends, and Brock instantly recognizes her from her clean sweep victory in the day’s sixth match. She introduces herself as Trinity and informs Misty that she’ll be her opponent in the third round. The pair exchange handshakes and wish each other luck for the next round.
The day of the third-round matches begins, where the top 16 will be whittled to the top 8 competitors. Misty calls out her Poliwhirl, and she is frightened when Trinity calls out her Gyarados. Misty tells Poliwhirl to use Bubble, but Gyarados quickly charges up a Hyper Beam that blasts the Bubble attack Poliwhirl out of the match. Misty remains confident and orders Corsola onto the field. At Trinity's command Gyarados uses Hydro Pump, but Misty has Corsola sends it back with Mirror Coat. Gyarados fires a Hyper Beam to send the torrent of water towards Corsola. Though Corsola dives down and the beam blows up behind it. Waiting a while, Misty finishes Gyarados off with Spike Cannon. Trinity then sends out her Chinchou. Trinity has Chinchou aim its Spark at the sky. The electricity mixes with the clouds before firing down on Corsola. Corsola manages to defend itself with a Mirror Coat and sends the attack back at Chinchou. Chinchou, however, appears unfazed, while Corsola is showings signs of exhaustion. Chinchou follows up with a Confuse Ray, but Corsola dives underwater to avoid it. Chinchou dips its antennae into the water to use Confuse Ray again, and this time Corsola gets confused. With Corsola acting delirious, Chinchou finishes it off with a Water Gun. Misty is defeated, and Trinity moves on to the top 8. That evening, Trinity meets with Ash and his friends at the Center. Misty congratulates her and wishes her good luck for the next round.
Trinity calls out her Golduck to go up against her opponent's Feraligatr in the finals of the Whirl Cup. Just before the battle begins, however, Team Rocket shows up in their balloon. Jessie uses a fishing rod to snag the Sea Spirit staff but Pikachu comes in and uses a ThunderShock to snap the line. Officer jenny realizes the Team Rocket trio was behind the recent threat. The announcer brings everyone’s attention to the odd balloon in the sky, pausing the Whirl Cup momentarily. It's now a no-win situation for them, Ash and Misty send out Totodile and Poliwhirl, while Trinity's Golduck and her competitor’s Feraligatr all launch a combined Water Gun at the trio. Pikachu then finishes them off with Thunderbolt. Maya is grateful for the Trainers’ efforts, and Misty stops Brock from flirting with the Sea Priestess. Misty calls out to Trinity to wish her luck, and the competition match resumes.
By evening, the six days of competition have drawn to a close and the award ceremony begins. Trinity's unnamed opponent is gifted the Mystic Water pendant, with Trinity winning second place. Maya once again raises her staff up towards the setting sun and it starts to glow. The next day, Trinity, Ash, and his friends watch the Colosseum once again flood as they reminisce about the good times they had competing in the Whirl Cup.