Items: Hat Rack, Joke Glasses, Mystery Bag, Power Oil, Shortcake
When you enter the caverns this time, you'll find Doug waiting. He jumps up and attacks the rock with all his strength, but nothing happens. He suggests that you find his brother Digby. Together, Doug and Digby should be able to destroy it. Doug sends you to Monster Village to find him.
When you enter the village, you'll find Digby chilling out near the center, next to the fire. Talk to him and he'll head off toward the cave. Leave the village now and return to the cave. Doug is there but Digby isn't. Apparently, Digby is 'directionally challenged.' You have to find him again. Leave the cave and this time head to Fountain Clearing, where you first got your fire attack in the forest to the west. That's where Digby ended up on his way to the caverns. You'll find him standing by the fountain. Talk to him and he'll burrow into the soil and disappear after promising to head to the cavern.
Leave the forest and this time head to Asparagus Lake. He's standing just past the entrance, to the right toward Pecky's vacation home. Talk to him and he'll head out of the area, above ground this time. Now you can return to Bracken Hollow. Digby is there, along with Doug. Talk to them now and they'll give the giant stone a shot. Through their powers combined, the Super Mole Brothers break through the barrier and you're free to proceed.
When you appear in the next room, familiar iron grating snaps shut behind you. You're stuck now. No turning back. The room in which you find yourself is full of pots. There's a sign ahead that warns you of danger with a skull sign. That's a good hint that you should equip the Gas Mask. Do so, then break the pots and other debris scattered around the room. There's a weak wall to your left and another to the right. Use a power drill to bust through the one on the left and you'll find a lever that you can pull. Do so, then head back into the main room. This time, bust through the other wall. Pull the lever there and you'll cause the grate in the main room to disappear so that you can proceed into the next area.
In this room, directly ahead, you'll see what looks like a blue, spiked ball encased in giant icicles. You can drill through the ice to reveal the sweet little enemy inside. A few more swipes of the drill and he'll disappear while leaving coins behind. There are a total of three of them. Once you defeat them all, the next door will open and you can proceed into the next area.
From where you appear in the next cavern, you'll notice that it's full of pots and stalagmites. There's a sign that says something about inserting a coin, as well. Break all of the stalagmites and pots for coins, then examine the button on the wall, just left of the sign. There's a slot for coins and you can put in 10. Go ahead and do so. You've made at least that destroying the room, anyway. Your reward is a Phantom who drops down the chute and attacks you while clad in plenty of armor. Use charged shots to defeat him and grab some junk.
At this point, you should consider inserting more coins (though you can always come back and do it later). Each time you insert coins, you'll cause a new Phantom to come, tougher than the previous one. This is a great way to collect a bunch of Junk and even coins, since some of the later ones start dropping huge wads of cash worth several thousand. Keep inserting coins until you insert two thousand and it calls forth a heavily armored Phantom that can really make your life miserable. Keep pressing him back against a wall and corner him to use repeated launch attacks and drain his life. When you win, he'll drop a bunch more cash. Go to the slot and insert another two thousand coins to receive a gift box that contains JOKE GLASSES. They'll make you the life of the party! They're not equippable, just an item you'll need to give to your friend Chucky at some point in the future.
When you're done getting your swag, or if you've decided to come back and do it later (though you'll want to be sure not to forget), head to the opposite side of the room and pass through the dark opening and into the next area.
You're up on a ledge, and as you look to the right you'll see three Phantoms conferring. They have question marks over their heads, which means they're confused enough that you can mount a good surprise attack if you're so inclined. Go ahead and drop down to their level, then rush in with a charged shot. Follow that up with some Drill Tornado attacks and they should be gone before you know it. Now you can backtrack to take care of the debris you initially ignored up top. The stalagmites give plenty of coins. When you're done, return to the level where you startled the three enemies. To the right, there's a pit filled with a murky substance that comes up to your shoulders. Wade through it back toward what you'll find is a weak wall and drill through it. You'll find another low corridor. Wade through the soup and use a partially submerged rock to climb up the bank to a treasure chest. It contains POWER OIL. Break the pot open, too, then return yet again to the area where you surprised the three Phantoms. To the left of where they were huddled, there's a weak wall. There may also be a plant if you haven't already destroyed it (defeat it now if you haven't already). Drill through the wall.
Through the newly-created opening, you'll find three pots you can break open for plenty of copper coins. Then jump up and destroy some stalagmites. Flip the lever you find and stand on the health refueling pad if necessary. Then pull the lever to make some crates fall, back near this chamber's entrance. A spiked ball dropped, as well, and has begun to swing pendulum-like. Head back to where the crates fell and use them as steps to the lever (while giving yourself plenty of time to sneak past the spiked ball). When you pull this one, the grate near the energy recharging pad will slide open so that you can proceed into the next room. Fill your life back up if you need to after an encounter with the spike ball while flipping the switch, then pass through the doorway and into the chamber beyond.
This may be a good time to switch to the goggles, if only briefly. There are some bats flapping their way around in the air over some murky water ahead. You'll take damage if you fall in, but not when you wear your goggles. Swim through the area, jumping out of the water and hitting the targeted enemies. There are three or four bats. Once they're gone, work back toward the entrance and start breaking the various items. For instance, there's an alcove nearby where you can break a blue container for some Junk. Near it, there's also a crate. Push it onto the switch, then swim back around along the tunnel and to another ledge with another crate and switch. When you slide this one over the switch, you'll cause a door at the end of the room to open.
Head toward it. Near the end of the deepest water, stop swimming in any direction and just tread water. After a second or two, Parin will slowly allow herself to sink deeper and deeper into the water, down a submerged passage. To the right, there will be a narrow hole you can swim through. Do so and you'll find a secret chamber that contains a treasure chest holding SHORTCAKE. This chest took me forever to find. I didn't realize you could dive. Anyway, grab it and break the pig vase apart for some coins, then dive back through and proceed to the end of the watery area where you fought the bats. There's a staircase leading out of the water. Once you reach it, switch to your gas mask.
As you walk toward the door, expect several sets of enemies to attack. You can run through the opening if you like, but that will affect your rating for the level and cause you to miss a nice item. Besides, these guys carry a lot of armor that you can turn into Junk. You actually do want to face them. Just be ready to use a lot of charged attacks, since many of them can't be hurt otherwise. Finally, the last set of enemies carry cannons around on top of their heads. When you see them come, it's time to eliminate them quickly with some Drill Tornado attacks. Once you defeat them, you'll be free to check the area for destructible debris. Don't miss breaking the purple vase, either.
You're still not ready to pass through the archway, though. Make sure you're wearing the goggles again, then jump into the pools of water nearest the door and swim against its left bank until you find a narrow tunnel leading beyond the room's left side and into a hidden room. There you'll find a treasure chest that contains the MYSTERY BAG (take it back to Pamela in Tiese Town for some POWER OIL). You can also drill a stalagmite for coins. Now return to the main room and go ahead through the door.
You've made it to the treasure room now. Step onto the altar and grab your reward, the HAT RACK. Then you'll be taken out of the area and to the world map. Return to Monster Village and give the hat rack to Pierre. His happiness will cause more Dark Mist to drift off the map, revealing new areas you can explore to the west and northeast. Head to the map, and begin your search just to the east of the level you just completed.