On the way to Solaceon Town, our heroes reach a river with an unfinished bridge. Brock immediately falls for Isis, the stonecutter working on the bridge, and learns that construction has halted because Isis's Bibarel refuses to cut any more stone. With only days until the project deadline, Isis's job is in trouble, and Brock gallantly offers to help get Bibarel back to work. But to his surprise, even the lure of delicious Pokémon food can't convince Bibarel to resume cutting.
Isis doesn't know what's wrong—Bibarel was trained by a master stonecutter and always used to obey her commands. But once the stonecutter left, Bibarel stopped working. Brock and his friends try to make up for the slack by having their own Pokémon cut stone instead, but without Bibarel, they don't have the know-how to cut stone to the right specifications. To make things worse, Team Rocket descends on the scene and steals the construction team's Machamp and Machoke!
Bibarel beats Team Rocket and frees the kidnapped Pokémon, but the bridge's head engineer shows up at the quarry and tries to force Bibarel out of the way so work can resume. With help from our heroes, Bibarel defeats the head engineer and his Pokémon. Then Bibarel's original master returns, and reveals that the head engineer's blueprints were flawed. That's why Bibarel refused to cut any stone! Using the corrected blueprint, Bibarel gets back to work and the bridge is finished on schedule.
Ash and his friends are on their way to Solaceon Town, when they come across an incomplete bridge which has a group of people standing on it. Brock falls in love with one of them, assumes that she is being threatened and races towards the bridge, but when he gets there, he does not stop soon enough and Croagunk has to save him. He is then told that the Mayor and the head engineer are simply telling the woman, called Isis, that the bridge must be completed soon, causing Brock to apologize. The Mayor and head engineer then leave, with the head engineer commenting that they have to think about his reputation. Ash and Dawn remark that he is very selfish, and everyone introduces themselves.
Isis tells Ash and his friends what is going on. Originally, an expert stonecutter was hired to build the vital bridge, but he hurt his back. Then the head engineer took charge and put Isis in charge of stonecutting, but work has since ground to a halt. Before she can continue, Brock tells her to leave it all to him and gives some of his special Pokémon food to the construction company's Machoke and Machamp. Isis is amazed at the eagerness at which they eat the food, but then says that they are not the problem, it is the Pokémon which cuts the stone which is. At Brock's request, Isis leads them to the quarry. Meanwhile, Team Rocket contemplates taking the Pokémon, fantasizing about building a giant stone castle for the boss.
When they get to the quarry, Isis points out the stonecutter: a sleeping Bibarel. Brock then pulls a table and ingredients from his bag, before making a large bowl of food for Bibarel, which eats the lot before going back to sleep. Isis then reveals that she is actually a professional Pokémon Breeder, and that she was the one who taught Bibarel to cut stone before showing it to the expert stonecutter. The stonecutter took it under his wing, helping Bibarel to master stonecutting. She then says that since the stonecutter hurt himself, Bibarel has refused to work. Brock, as a Rock-type expert, decides to help, borrowing Chimchar, Buizel and Turtwig and sends out Sudowoodo. Chimchar heats up the rock with Flamethrower, Buizel cools it with Water Gun, causing it to crack, and Turtwig uses Razor Leaf, which Sudowoodo copies with Mimic, to break it off and cut it into smooth blocks. Isis measures it and tells them that the blocks are the wrong size. They are about to try again when Bibarel stands on the blocks they cut and looks at them angrily.
Suddenly, the cries of Machoke and Machamp break the deadlock, and Team Rocket's balloon appears over the trees with the Pokémon in a cage beneath it. They perform their motto and Meowth pushes a button, causing an arm to shoot out. The others try to free Bibarel the same way they cut the stone, but the arm is not even scratched. Team Rocket then throw Bibarel into the cage. It angrily begins gnawing on the bars, and although Jessie and James are initially worried, Meowth says that the bars are made of the same material as the arm, so it will not break. However, Bibarel quickly breaks through the bars and all the Pokémon jump out. Pikachu then sends Team Rocket blasting off again with Thunderbolt.
Bibarel still refuses to cut stone, however, and the head engineer shows up in a giant digger and sends out his Rhydon to cut the stone with Horn Drill, ignoring Isis's and Brock's reminder that he will need Bibarel's help to cut the stone into the right shape. Bibarel angrily tackles Rhydon, which then hits it with its tail. Rhydon is about to stomp on Bibarel when Bibarel bites Rhydon's foot. The head engineer then sends out his Aggron, Magmar and Metang, telling them to use Iron Head, Flamethrower and Metal Claw, respectively. Bibarel dodges the Iron Head and Metal Claw, but is hit by the Flamethrower. The head engineer's Pokémon all charge at Bibarel, while Isis realizes that Bibarel is trying to protect the quarry.
Ash tells Pikachu to use Iron Tail, which hits Rhydon. Then Chimchar uses Flamethrower, Buizel uses Water Gun, Turtwig uses Razor Leaf, which Sudowoodo copies with Mimic, and Piplup uses Bubble Beam. The combined attacks stop the head engineer's Pokémon, so he jumps into his digger and drives it towards the quarry wall, but a large rock comes out of nowhere and knocks it over. Finally, the expert stonecutter reveals himself with a third Machamp. The stonecutter reveals that he never really hurt his back, and the only thing that needed healing was the blueprint. The head engineer denies this, but the stonecutter points out that it required less stones than necessary, and reveals a model of the bridge he had built to the blueprint. When the removes the support structure, the bridge immediately collapses. The head engineer says he continued building it so the project would be finished on time and his reputation would be saved.
Isis and the expert stonecutter tell him that he will never work as an engineer alongside stonecutters again, and that he must leave the construction site immediately, or else. Threatened by the Pokémon, the head engineer and his Pokémon run off. Despite this, Isis realizes that they will never get the project finished on time without a blueprint. The expert stonecutter then reveals that he had already made a new blueprint for the bridge, so everyone starts working together. Ash and friends' Pokémon combine their attacks and Bibarel cuts the stone blocks to the right size and shape. The other Pokémon then start carrying the blocks to the bridge, while Ash, Dawn, and Brock help to build the bridge itself.
At the opening, the group watches from an overlook and the expert stonecutter gives the group headbands like his and Bibarel's. Brock immediately puts his on and starts swooning over Isis, before he is Poison Jabbed by Croagunk, causing Isis to comment that Brock does not look so good as he collapses. After waiting a few moments for Brock to recover, the group waves goodbye, and they continue on their way to Solaceon Town.