After you defeat the Axem Rangers and get the Star Piece, the Nimbus Land Royal Bus is repaired, and it takes you to Bowser's Keep.

Explore Bowser's Keep

If you have Bowser in your party, there is a chance that some enemies will run away from battle.

After the cutscene, go northeast. You can either run past the Terra Cottas (Koopa Troopas) or battle them. They chase you if you get too close. Go northeast.

Carefully cross the bridge while battling or avoiding the Gu Goombas. Then try to jump across the floating platforms, which will fall if you stand on them for too long. Go northeast.

There are two Gu Goombas beside the door. After you have gone partway northeast, the Gu Goombas will jump toward each other, then they will run northeast along the path, so if you aren't fast enough or you don't jump soon enough, you will have to battle them. Go northeast and battle or avoid the Malakoopas, then go through the northeast door.

This room is dark, so carefully make your way along the path, battling or avoiding the Gu Goombas on the way. When the path splits, you can optionally go northwest, but a Gu Goomba will charge forward at you, so be prepared to jump if you don't want to fight it. Then go northwest to get a healing mushroom. Go southeast, battle or avoid the Malakoopa, and be aware that there are some Gu Goombas hiding behind the statues along the northeast path. If you slowly approach the first one, it will jump out and start bouncing up and down, and you can walk up against the statue to avoid it if you wish. If you slowly approach the second statue, you won't have to battle the second Goomba at all. Go through the northeast door.

Go northwest until you are up against the wall, then go southwest to a secret room where you can get coins and a healing mushroom.

Go back to the previous room and use the Save Block. You can talk to Croco to buy healing items, and some armor.

Go northeast to find six doors. Two of them lead to action courses, two lead to battle courses, and two lead to puzzle courses. You won't know where they lead until you go through, and you can't go back to the six doors until you complete the course you're in (but you can always save first, and reload your save if you end up in a course that you don't want to do). Each action and battle course has a weapon reward at the end, depending on which course it is. One of the battle courses starts with Gu Goombas, and the reward at the end is the Star Gun, a weapon for Geno. The other battle course starts with Terra Cottas (Koopa Troopas), and the reward at the end is the Drill Claw, a weapon for Bowser. The puzzle courses have Rock Candy as the reward. For the action and puzzle courses, click the room description to see the guide for it.

• A room full of lava, with a floating platform up ahead
• A room full of lava, with enemies that jump onto invisible platforms
• The yellow platform takes you to a Hammer Bro with a treasure chest in front of him
• The yellow platform takes you to a Hammer Bro standing on steep stairs

Action Course 1

If you're in a room full of lava, with a floating platform up ahead, a message tells you that you get 10 tries to get through the course. Jump onto the moving platform, then carefully jump from platform to platform, trying not to fall into the lava. Be sure to wait for the platform to not be at its highest point, because you will hit the ceiling, which might make it hard to jump the correct distance. You can stay on the final platform when it goes all the way up, and get off at the floating platform at the top, then go southwest to get a Croaka Cola/KeroKeroCola. After that, go to the northeast end of the room and go through the door.

You have to jump onto the cannonball and use the directional pad to move around. Try not to jump off of the cannonball when it's behind a pillar, because it may be difficult to find it again. You can't battle the bombs, and if they hit you, you lose some coins and lose one of your 10 chances. You don't have to stay on the cannonball the whole time, so you can try to jump off and lure the bombs away before running back to the cannonball. You can reach the coins and treasure chests only if you're standing on the cannonball. From left to right, the chests contain a Pick Me Up, a Flower, a Max Mushroom, a Rock Candy, and a Flower. When you're done, go to the northeast end of the room and go through the door.

When you jump on a floating platform, the other platform spins around. Jump from platform to platform to make your way across the room. From left to right, the chests contain a Flower, another Flower, a Royal Syrup, a Pick Me Up, a Fire Bomb, and a Croaka Cola/KeroKeroCola. When you're done, go through the northeast door.

Open the chest to get the Sonic Cymbal, a weapon for Mallow. Go through the northeast door to return to the hallway with 6 doors.

Action Course 2

If you're in a room full of lava, with enemies that jump onto invisible platforms, you can follow the Koopa Troopas (and can't battle them) to help make sure you don't fall off. The chests from left to right are a Fright Bomb, an Ice Bomb, a Royal Syrup, and a Rock Candy. If you go northeast from the entrance, you can hit the chest to get the Fright Bomb. After that, carefully go southeast, but not too far, or you will fall. Go northeast to the chest and open it to get a Royal Syrup. Then go slightly southwest, then northwest until you're standing southwest of the next chest. Go northeast and hit the chest. Then you can go northeast until you're standing northwest of the next chest. Go southeast and hit that chest. If you're careful, you can go southwest until you're in front of the right side of the second window, then run and jump to the exit. Go through the door.

There are platforms here that move back and forth in consistent patterns. Just learn the patterns and you can carefully jump or walk across them. From left to right, the chests contain a Red Essence, a Max Mushroom, a Flower, and a Fire Bomb. Go through the northeast door.

In this room, you have to jump up the platforms and ledges while dodging the barrels that the Chained Kong at the top of the room keeps throwing, much like the original game of Donkey Kong. Some of the barrels will go the long way along each ledge, but sometimes there will be barrels that will roll straight toward the entrance that you came from. Whenever a barrel hits a platform, it will bounce, so you can temporarily be safe if you stay next to a floating platform, but you might also get hit by a barrel that rolls toward the entrance. The barrels also can't hit you if you are up against the northeast wall of a ledge. When you reach the top and bump into the Chained Kong, it will run away. Go through the door.

Open the chest to get the Super Slap, a weapon for the Princess.

Puzzle Course 1

If you're in a room with a yellow platform that takes you to a Hammer Bro with a treasure chest in front of him, jump onto the platform and Dr. Topper will tell you about the coin game: there are 21 coins in the box, and whoever takes the last one is the loser. To make things more difficult, the game won't tell you how many are left in the box, so you have to just keep count and remember how many are left. You can take up to four coins per turn. Jump once to take one coin, jump twice to take two, and so on. If you want fewer than four coins, press A after you have taken however many you want—but you're required to take at least one. Here is how to win:

Afterward, you will automatically go to the next room, where Dr. Topper introduces the Magic Button puzzle. Jumping onto a button will also reverse the four surrounding buttons. (You can't accidentally walk onto a button—you can only hit a button by jumping on it.) Your goal is to turn all the buttons off. Here is one way to do it (click to display it):

 
O O 4 O
2 O O O
O O O 3
O 1 O O

Afterward, go northeast. Dr. Topper will explain Ball Solitaire (a variant of Peg Solitaire). He will make one ball disappear. You can stand next to a ball and press A to kick it in the direction you're facing. You can kick a ball over another ball if there's an empty spot beyond the second ball, like so:

Mario → Ball → Ball → Empty spot

The ball after the one you kicked will disappear. The goal is to have only one cannonball remaining at the end.

Here is one way to do it:

k = ball to kick

o o . o
o o o o
o o k o
o o o o
--
o o o o
o o . o
k o . o
o o o o
--
o k o o
o o . o
. . o o
o o o o
--
o . o k
o . . o
. o o o
o o o o
--
k>o . .
o . . o
. o o o
o o o o
--
. . o .
o . . o
. o o o
o o k o
--
. . o .
o . o k
. o . o
o o . o
--
. . o .
k o . .
. o . o
o o . o
--
. . k .
. . o .
. o . o
o o . o
--
. . . .
. . . .
. o o o
k o . o
--
. . . .
. . . .
. o o o
. . o k^
--
. . . .
. . . o
. o o .
. . k .
--
. . . .
. . o k
. o . .
. . . .
--
. . . .
. k . .
. o . .
. . . .
--
. . . .
. . . .
. . . .
. o . .

Go through the door afterward. Hit the chest to get a Rock Candy.

Puzzle Course 2

If you're in a room with a yellow platform that takes you to a Hammer Bro standing on steep stairs, he gives you a quiz. Luckily, the timer doesn't start until after you press the button after you read the question. Beware of choices that look similar to the correct answer but are misspelled! Here are the questions and answers:

Afterward, you automatically go to the next room, where you have to figure out how many barrels there are in the pile. But, just before the countdown starts, Dr. Topper will hide the barrels and add more of them. You might find it helpful to count the number before Dr. Topper changes it. The pile starts with 12 barrels After he adds more barrels, there will be a countdown. This is when you should try to count how many barrels there are. After the countdown is done, Dr. Topper hides the barrels and gives you three choices. Pick the correct number of barrels to continue to the next stage. This time, you don't get to see the barrels before the countdown starts.

After that, you automatically go to the next room, where Dr. Topper introduces Boo, Goo, Bones, and Kipp. He says they competed in a triathlon, which included swimming, cycling, and a marathon. You have to talk to each of the four monsters to listen to their story. NOTE: In a triathlon, there are no breaks between each event, so the overall winner is whoever won the marathon.

The Clues

"I placed the same in the swimming and cycling events, but 2 others beat me in the marathon."
This one is saying that they were 3rd in the marathon, and 1st, 2nd, or 4th in swimming and cycling.

"I fell into 4th place during the bike race, but finally ended up in the same place as I did in the swimming event."
This one is saying that they were 4th in cycling, and 1st or 2nd in swimming and the marathon. (Can't be 4th because that would be the same as their cycling, and can't be 3rd because "finally ended up" refers to this person's place in the marathon, and the person from the previous clue was 3rd in the marathon.)

"I outrode _(4th in cycling)_ on my bike, and _(4th in cycling)_ was never able to pass me!"
This person stayed ahead of (4th in cycling), who "was never able to pass" them throughout the remainder of the event (both cycling and the marathon). Since (4th in cycling) was 1st or 2nd in swimming and the marathon (see above), we know that (4th in cycling) must have been 2nd in swimming and the marathon since they never passed this person, so therefore this person was 1st in the marathon.

The Final Answer

Therefore, the answer is:

1st place:

 
"I outrode _(4th in cycling)_ on my bike, and _(4th in cycling)_ was never able to pass me!"

2nd place:

 
"I fell into 4th place during the bike race, but finally ended up in the same place as I did in the swimming event."

3rd place:

 
"I placed the same in the swimming and cycling events, but 2 others beat me in the marathon."

4th place:

 
"I came in 3rd for swimming..."

Afterward, go to the next room and hit the chest to get a Rock Candy.

After Four Doors

After you have succeeded in four doors, you end up in a room with an exit in the east corner. Go through that exit and you fall near a Save Block. Use it, then go through the door, and you will battle Magikoopa.