The gang is going to the Battle Dome. May looks upon her egg and her ribbon, while Ash trains his Pikachu. Pikachu uses Volt Tackle, but Pikachu fails. May tells him to relax, while Max sees that there is a lake nearby. They are shocked when they arrived - the lake is deserted. They also see the boathouse deserted, though they are allowed to use the fishing poles, to which they do. Brock tells them they need to be relaxed to catch a fish, to which Ash is too relaxed - he falls asleep, but soon wakes up. Suddenly, he gets something, but it is heavy, so May, Brock, Max and Pikachu grab Ash. Ash manages to bring the thing out - it is a giant Crawdaunt.
Ash sends Corphish to battle Crawdaunt. Crawdaunt charges with ViceGrip, so Corphish does the same. Still, Crawdaunt is moore powerful, so Corphish is attacked. Crawdaunt uses Crabhammer, so Corphish does the same, but as before, Corphish gets hit. Crawdaunt uses Bubblebeam, so Corphish retaliates with the same attack, but gets hurt. Crawdaunt destroys the the fishing poles, so a woman comes to get it away, to which Crawdaunt goes back to the lake. Brock flirts with the woman, named Tiffany, so Max pulls his ear. They apologize for getting the fishing poles, to which she does not matter if they did. She tells them the lake was beautiful and was a popular place for fishing, until one day men came to convert the place to a spa. She told them to leave, to which they did. However, the Crawdaunt came and terrorized the people, so they left. Ash vows to get Crawdaunt out, using Corphish.
Suddenly, an older woman (who is Tiffany's grandma) disagrees with them. Still, with their confidence, grandma thinks there is a possibility. Ash, May, Max and Brock go to search for Crawdaunt. Soon, Brock and Tiffany spot Crawdaunt going in a cave, so Brock sends Marshtomp to warn the others. Crawdaunt comes to the men and is offered food as a reward. The gang has arrived, so Tiffany identifies the men to be the same ones from her story. Team Rocket, dressed as businessmen, see the area, but want something to eat first, so the man orders to get food. The man tells to take care of the boathouse, so Tiffany tells them they will not. Ash and Tiffany accuse the man for sending Crawdaunt to scare people, so the man acts dumb as he offered it food. Ash wants to battle, so the man tells if Ash wins, they will leave, but if he wins, he will get the lake and the boathouse.
The fight will be tomorrow, though the man tells them he will have the filthy lake. He was fishing once and was dragged to the bottom of the lake. He was trapped in the line of the fishing pole and almost went out of air. He survived, but he does not know how. Still, he wants to get the lake for his own needs. Later, Ash trains his Pokémon - Pikachu charges with Volt Tackle and Corphish uses Crabhammer, so they bounce off. Grandma tells them he will not win - she sends Vaporeon as a challenge. Corphish uses Crabhammer, though Vaporeon dodges. Corphish goes after it and attacks, but Vaporeon uses Acid Armor, vanishing. Next, Vaporeon uses Quick Attack, damaging Corphish. Corphish stands up, but is engulfed in lake grass. Vaporeon uses Hydro Pump, pushing Corphish on rocks and defeating him. Grandma tells Ash Corphish is powerful, but Crawdaunt is much more powerful, so Ash needs to adapt to the battle field and the situation he is in. Ash tells Corphish they will have to train.
Next day, the man comes with Crawdaunt. Corphish starts with Crabhammer and Crawdaunt does the same, but this time the powers are matched. Corphish uses BubbleBeam and Crawdaunt does the same, but Crawdaunt is more powerful, so Corphish moves away. Crawdaunt uses ViceGrip, but Corphish dives in, evading the attack and hurting Crawdaunt with Crabhammer. Crawdaunt charges with ViceGrip, but Corphish protects himself and retaliates with Crabhammer, pushing it onto a rock. Suddenly, Crawdaunt and Pikachu are taken by Team Rocket! They fly away, so everyone goes to get the Pokémon back. Corphish uses BubbleBeam, Squirtle Bubble and Marshtomp Mudshot, but Team Rocket dodge. Squirtle goes on top of Corphish and is launched, so Squrtile uses Rapid Spin, but there is not much effect done.
Marshtomp uses Water Gun, keeping Squirtle on the air. Squirtle uses Rapid Spin, and along with Corphish's Bubble Beam, destroys the machine. Pikachu and Crawdaunt come back, but the machine is thrown in water and Team Rocket is blasted off. Everyone is washed on shire, except for the man. Grandma goes to rescue him, to which she and a Dragonair succeed. The man remembers that they did the same before when he was a child. The man asks why did she rescue him, so she replies it was for the love of the lake. The man thanks Dragonair, who goes into the water. Ash reminds him of the battle, but the man cancels it - Tiffany and her grandma can have the lake.
They all hear Dragonair's roar - the Water Pokémon, who left, return back to the lake.
- Team Rocket's mecha bears a striking resemblance to ED-209, a robot from the RoboCop franchise.
- The Japanese title was originally ハクリュウの湖, but this was changed the day after AG151 aired to have the correct spelling of Dragonair's Japanese name, ハクリュー.
- A short 5-second countdown with animation based on the Advance Adventure opening is prepended to the broadcast.
- The OP animation changes a third time:
- The Team Rocket scene now includes Jessie's Dustox, but Weavile is removed.
- The Mew and Lucario scene is replaced with a scene based on Pokémon Mystery Dungeon.
- This was most likely done as Pokémon Mystery Dungeon was released in Japan on the same day as this episode premiered.
- The dub title is a reference to the 1981 film On Golden Pond.
- During the battle, Ash has Corphish dive underwater to dodge ViceGrip. Less than a second later, Crawdaunt lands on exactly the same spot where Corphish was able to be completely submerged and the water only comes up a few inches, thus having Crawdaunt stand on water.