This episode (and the one before it, actually) uses some music from the Manaphy movie. Which is the first time the anime's done this, IIRC.
-The gang is walking up a mountain road. As they round a corner, they see an unfinished stone bridge and some people standing on it in the distance. Takeshi looks at the people and immediately picks zooms in on a pretty girl. He also notices two men yelling at her, causing her to back up toward the part of the bridge that isn't finished yet! Takeshi immediately takes off and runs through the mountain, but he runs with too much enthusiasm and goes straight off the bridge! Takeshi falls, but luckily, Gureggru grabs his hand at the last minute and pulls him up to safety. Takeshi thanks his pokemon.
-Now, the three people on the bridge notice Takeshi's presence. The larger of the two men, wearing a construction hat, asks him what he's doing there. He then turns back to the girl and tells her that she only has three days to finish the bridge or else. The older man then adds that if she can't finish the bridge in the time given, they'll have to give the job to someone else. The two men turn around, get in their car, and drive off, leaving the girl with Satoshi-tachi.
-Takeshi takes this opportunity to introduce himself. The young girl, Ishisu, starts to tell Takeshi-tachi that they wanted to build the bridge because it's very inconvenient to go from the village to the town without it. However, a few days ago, the pokemon who were helping her out stopped working, halting any progress! Takeshi and his friends are taken to an area where two Goriki and two Kairiki are lounging about. After Satoshi mentions that Takeshi is a Pokemon Breeder, Takeshi breaks out his pokemon food and gives one dish to each worker. The pokemon perk up and eat the food, becoming energized! Takeshi thinks he's done it, but Ishisu reveals that those aren't the pokemon she was talking about! Depressed at the amount of time he's wasted, Takeshi asks where her pokemon is. Ishisu says that she'll lead them to its location.
-Meanwhile, the Rocket-Dan are behind some bushes, plotting. Musashi imagines that they can use the pokemon to make their Secret Base, but Nyasu says they should give the pokemon to the boss instead. That way, they can build a giant stone castle for Sakaki, complete with a giant castle wall!
-Our heroes eventually reach a rocky area where a Beadull wearing a headband is sleeping on a rock high above them. Hikari looks up at the pokemon and notes how it has no energy, but Takeshi says that it won't be a problem. He takes off his backpack and starts setting up a kitchen (he even pulls a *table* out of his bag), working on Beadull's food. When he's finished, he attaches the dish to a fishing rod and eases the food up to Beadull's location. The pokemon sniffs the food, gobbles it up, and then turns around and goes back to sleep! Surprised, Takeshi wonders if there's something wrong with his food.
-Ishisu starts to blame herself and reveals that she was also a Pokemon Breeder! She then has a flashback, saying that Beadull used to be able to shape perfect stones with its teeth. Next, we see that Beadull and Ishisu are being watched by a construction guru. The master tells Ishisu that while Beadull is talented, he can hone its skills even further. So, Ishisu agrees to let Beadull train with the old man. The flashback ends, and Ishisu tells our heroes that Beadull won't do any work now since it's master isn't around. Ishisu demonstrates by asking Beadull to help her make the deadline, but Beadull refuses. Takeshi says he will help, saying that his experience as the Nibi City Gym Leader back in Kanto will help him (?). He asks to borrow Satoshi's Buoysel, Naetle, and Hikozaru. Next, Takeshi calls out his Usokki. Then, Hikari's Potchama volunteers to help. As Beadull notices all the pokemon who just arrived on the scene, Takeshi starts issuing commands. Hikozaru is told to use Flamethrower on a rock that juts out. Then, Buoysel uses Water Gun to suddenly cool the rock, causing ti to crack. Next, Naetle uses Razor Leaf and Usokki uses Mimic-Razor Leaf to cut the rocks into four piecces. Potchama starts to cheer until Hikari states that it hasn't done anything.
-Ishisu goes to the four stones cut by the group's pokemon and starts to measure them, but she says that they're not the exact size that she needs. Takeshi says that the only thing they can do is try again, but before he can, he notices that Beadull is staring at them. The pokemon looks angry...
-Beadull continues staring out our heroes, and it's pretty obvious that it isn't happy with other pokemon trying to butt in on its territory. Before anything can happen, though, our heroes hear Goriki's and Kairiki's voices in the distance. Then, they see the Rocket-Dan's balloon! After the trio performs their motto, we can see that the strong pokemon are in a cage being pulled by the balloon! Without wasting any time, the Rocket-Dan use their Magic Hand to grab Beadull. Immediately, Hikozaru is ordered to use Flamethrower on the arm part, Buoysel uses Water Gun, and Naetle and Usokki use Razor Leaf. However, much to our heroes' surprise, the attacks don't break the arm! Nyasu laughs and says that they've made the arm especially resistant. After throwing Beadull into the cage with the other pokemon, Beadull tightens its headband and starts to gnaw on the bars. Before long, the beaver pokemon breaks through, and all the pokmeon jump out. Meanwhile, Pikachu climbs to the top of the cliff and uses a Thunderbolt on the balloon, sending the Rocket-Dan blasting off.
-Now that the Rockets are out of the way, Ishisu tells Beadull that it did a good job. Takeshi, seeing that the pokemon is energized again, asks Beadull if it'll help them build the bridge. The pokemon refuses. Suddenly, the director from before drives up in a backhoe and says that he'll do the work himself. He calls out his Saidon and orders it to use Drill Horn on the rocks, but Ishisu tells him that the cutting has to be perfect or else. As Saidon continues drilling through the rock, Beadull tackles the pokemon! Saidon swats it away with its tail and then goes over to the pokemon to stomp on it, but Beadull bits the rhino on its foot.
-Next, the director brings out his Bossgodora, Boober, and Metang. The three pokemon back Beadull into a corner, but the beaver pokemon doesn't give up! It jumps over Bossgodora's head and dodges a Metal Claw attack from Metang! However, Boober's Flamethrower attack does hit, weakening the pokemon. Beadull stands up and sees that the director's four pokemon are charging at it.
-At this point, Satoshi-tachi decide to step in. Pikachu uses Iron Tail on Saidon, knocking it out. Next, Hikozaru uses Flamethrower, Buoysel uses Water Gun, Neatle and Usokki use Razor Leaf, and Potchama uses Bubble Beam. These attacks hit the other three pokemon, knocking them out as well.
-Next, the director jumps into his backhoe and says that he'll do the work without the pokemon. At that moment, a rock thrown from offscreen hits the backhoe, tipping it over. The director looks up and sees that the source is the construction guru and a Kairki! Suddenly, Beadull perks up at the sight of its old master. The master joins our heroes below and says that the plans that the director is using for the bridge are flawed and that when the support harness is removed, the whole bridge will collapse! The master then accuses the director of being aware of this but continuing anyway, endangering everyone who works on it. The guru then tears up the director's plans. All of Satoshi-tachi's pokemon and the Goriki and Kairiki duos gang up on the director, so he and his four pokemon make a run for it.
-Ishisu is happy that her old master is back, but she wonders how they'll make the deadline without any blueprints. The master says he has that covered and takes out some blueprints that he made himself! Beadull gets pumped up and agrees to work on the bridge.
-Over what is assumed to be the next three days, our heroes help build the bridge. All the pokemon help carve/carry stones (Pipinku is seen carrying like six stones by itself).
-After the bridge is completed, fireworks are set off to celebreate. Hikari tells us that she's happy that they were able to finish the bridge on time, and Ishisu states that Takeshi was a big help. The guru said that the gang did well and rewards them with some headbands similar to the one Beadull was wearing. Takeshi, wearing the headband, starts to flirt with Ishisu, but he's quickly shot down by Gureggru.
Orchid-Hakase Big Encyclopedia: Hippopotas