With the Go-Goggles, you can finally venture into the windswept desert on Route 111. The powerful sandstorm deters most would-be explorers, so no one has yet claimed the valuable treasures lying among the dunes.
The unending sandstorm seems to have uncovered two treasures from the ancient past in the desert's northeast corner. The Root Fossil and Claw Fossil belong to two species that once lived in the primordial ocean. The researchers at Devon Corporation back in Rustboro are able to revive any Fossil they receive into a long-lost Pokémon. The Root Fossil becomes the Rock/GrassLileep, while the Claw Fossil turns into the Rock/BugAnorith. Removing either one from their resting place causes the other to sink into the sand, so choose carefully!
The unusual arrangement of stones to the south is known as the Desert Ruins. It is believed to mark the resting place of a legendary Pokémon. But with the entrance sealed, you won't be able to investigate until later.
Back to Petalburg City
Now that you've claimed your fourth Badge and combed the desert for treasure, your next stop is Petalburg City. The city is far to the southwest, but there are multiple ways to get there.
Petalburg City Pokémon Gym Leader: Norman
A man in pursuit of power!
The Petalburg Gym, which specializes in Normal-type Pokémon, is styled as a traditional dojo with multiple rooms. Each room has a single Trainer who uses special items to gain the upper hand in battle. The sign on each door gives a clue to the strategy of the Trainer in the room behind it. The first two rooms beyond the lobby are labeled "Speed" and "Accuracy". The three rooms farther on are named "Zero Reduction", "Defense", and "Recovery". The final two rooms before the Gym Leader are labeled "Strength" and "One-Hit KO". A minimum of three Gym Trainers must be defeated to reach the Gym Leader. Fighting types like Machop and Makuhita will give you the upper hand here.
In the final room, your father has been waiting for you. Now that you have earned four other Badges, he is now ready to accept your challenge. Norman leads with the first of his two Slaking. Slaking usually leads with Yawn; if you switch out your Pokémon to keep it from falling asleep, your next Pokémon will be safe from attack. This is due to Slaking's Ability, Truant, which prevents it from attacking every other turn. However, his Vigoroth has no such problem. In fact, the Pokémon is so restless that it can't sleep, due to its Vital Spirit Ability. All three of Norman's Pokémon know Facade, which doubles in power if the user is Burned, Poisoned, or Paralyzed, though the Attack penalty incurred by sustaining a Burn still applies. While Ghost Pokémon are usually unaffected by Normal-type attacks, and vice-versa, Norman's entire team can use Faint Attack to deal serious damage to such Pokémon.
Afterwards, your father awards you the Balance Badge, which boosts your Pokémon's Defense by 10% and enables the use of Surf in the field. He also hands you TM42 (Facade) as a gift. Norman then remembers that Wally's parents stopped by a short time ago, looking for you. Visit them in their home next to the Gym, and Wally's father gives you HM03 (Surf) as thanks for helping the young Trainer. In battle, Surf is a strong Water-type attack; in the field, it allows you to cross bodies of water.
When you return to Mauville, you find Wattson standing near the Pokémon Center. He asks for a favor, and explains that the city has an underground sector known as New Mauville. There's a generator inside that hasn't been functioning properly, and he needs you to go and turn it off before the situation gets out of control. He gives you the Basement Key and directs you to the facility's entrance on Route 110. Surf eastward under the north end of Seaside Cycling Road to reach the facility.
New Mauville, Entrance
New Mauville, B1F
New Mauville was intended to be an underground city extending dozens of floors below the surface. However, the project died in development when it was discovered to be a habitat for wild Pokémon.
Use the Basement Key to unlock the door, and step inside to reach the southeast room.
The lower floor uses a series of colored buttons as a security measure; when stepped on, all similarly-colored doors open while all others close. Step on the blue button in the entrance room and go west. Press the green button in the next room and continue on. Pass by the third button and head north to reach an Escape Rope; collect the item and press the blue button beneath it. Go northwest to find a room with two items, a Parlyz Heal to the left and a Voltorb to the right. Follow the hallway eastward to the north-central room and another pair of items, a Voltorb to the left and a Full Heal to the right; collect the item and step on the green button beneath it. The generator is located in the northeast room; press the red button to shut it down and collect the Thunderstone before leaving the area.
With your task complete, return to Wattson outside the Pokémon Center. Inform him that everything is all right in New Mauville, and the grateful Gym Leader rewards you with TM24 (Thunderbolt).
The seaside Route 118 links the west and east sides of the region together. Several new species of Pokémon can be found here, including Electric types that will be of great value in the upcoming Gym.
When you're ready to cross the river, approach the beach and use Surf. Hop on your seafaring Pokémon's back to glide across the water. While Surfing, it is impossible to use the field moves Cut, Strength, or Rock Smash; however, severalothermoves are allowed. The Itemfinder can't be used while crossing the waves, but you can use an Escape Rope or a fishing rod while doing so.
Get Good with a Good Rod
The Fisherman on the river's eastern bank believes that Good Rods are really good. Agree with his statement to receive your very own Good Rod, a mid-level fishing rod that can catch even more kinds of Pokémon than the Old Rod.
Gabby and Ty
After your first interview on the south side of Route 111, the intrepid news team can be found searching for their next story on the eastern bank of Route 118's river. Accept their challenge to another Double Battle and be sure to give them a great interview when the dust settles!
Meet up with Steven
As you leave the beach, you are noticed by Steven. He hasn't seen you since your first meeting in Granite Cave, and is pleased to see how much you have grown as a Trainer. He wonders if you will raise Pokémon of all types, or only a certain one.
Known for its sweltering heat and sudden rainfalls, the spacious Route 119 runs north from Route 118 to Fortree City. The area is filled with patches of tall grass, which hide Trainer and wild Pokémon alike. The extreme weather conditions make this an ideal setting for the Weather Institute, located on the north end of this tropical rainforest.
A handful of Trainers in the southernmost patch of long grass like to copy the movements of any Trainer passing by, collectively earning them the "Mimic Circle" nickname. They move when you do, so outmaneuver them to pin them down and start battling. Each one remains in a certain area, which gives you a chance to corner them.
A small cabin stands beyond the patch of long grass. Speak to the kind woman inside, and she'll let you and your Pokémon take a quick break to restore their health.
Located on the north end of the route, the Weather Institute is a high-tech facility used to study and research the intricacies of weather patterns across Hoenn. This research seems to have attracted the attention of Team MagmaR/Team AquaS, as several Grunts have been stationed outside.
Visit the back room to find some Team MagmaR/Team AquaS Grunts searching the place. Before battling them, head to the northwest room to find a comfy bed and rest your Pokémon before continuing on. There is also a PC here in case you should need to reorganize your team.
Looking for Answers
When you reach the second floor, you find the source of the disturbance: Magma Admin CourtneyR/Aqua Admin ShellyS is harassing the researchers! She is here looking for information about extreme weather conditions, and to steal one of the Institute's Castform, a rare species of Pokémon. She can't allow you to meddle in the team's plans, and draws you into battle.
The Admin simply shrugs off her defeat, claiming that the team has other plans before she and the Grunts leave the building. As thanks for your help, one of the researchers even rewards you with a new Pokémon, Castform, which changes its type and appearance based on the current weather.
Rival Battle 3
Leave the building and cross the upper bridge. May/Brendan catches up to you when you reach the nearest stairway. Your friend wants to see how much stronger you've become, and wastes no time challenging you to a battle!
Once you defeat her/him, your friend rewards you with HM02 (Fly). It's a strong move in battle and even more useful when used in the field, though you'll need to win the Gym Badge from the next city first. She/He then runs off, leaving you to continue on to Fortree City.