Super Mario RPG: Legend of the Seven Stars/The seventh Star Piece

First of all, head back to Moleville.

Moleville
Go to the item shop. The blue guy who was searching in the Coal Mines is now standing here to sell his discoveries. If you have not yet bought them, he will offer you a Lucky Jewel and a Mystery Egg, simply decline these offers and he will sell you a "Metal Plate" for 300 coins. Buy it and it turns out to be a Frying Pan which is the strongest weapon that Toadstool can get. Now, go to Nimbus Land.

Nimbus Land
Go into the castle and head to the King. Mallow tells his parents that he was able to find the Star Piece. The King notes though that you're still missing one Star Piece to complete the Star Road. As the Queen notices, the only place where you have not yet been is Bowser's Keep. To get there, they will organize a floating bus which will take you right to the entrance. Now go back outside and run to the stairs at the left. Talk to the guy there and the bus will arrive. Mario will jump on it and you will be taken to Bowser's Keep.

Bowser's Keep
Note: It is highly recommended to have Bowser in your party. His presence will cause most enemies in this area to flee.

Go forward and you'll come across the room where the Terrapins were the first time you were here. Go through the red door and cross the lava pit by jumping on the platforms. The next area is where you fought Bowser last time, but now, there are only some enemies here, so continue. The next area is pitch dark, just follow the way to the right and you will get out. Here you can find a save point if you need to save. Behind the save point is Croco. This time you don't need to fight him, but he will sell you some items. Stock up on anything you need, then continue forward.

Now begins a puzzle. There are six doors. Behind each door, there's a different thing you need to do. There are two Action doors, two Puzzle doors and two Battle doors. Behind which door they are is determined randomly.

Six doors
Note: for the two Action rooms, you have ten tries. You lose one try if you fall into the lava or otherwise fail your exercise.

Action room 1


This action room starts off with a large lava pit and several invisible paths that lead over it. A number of Terrapins walk around and as they jump, the paths will flash, allowing you to see them. However, the Terrapins will eventually run off into the lava, from which on you're on your own. There are some coins on your way, and a few Treasure Boxes - they contain a flower, a Royal Syrup, an Ice Bomb and a Rock Candy.

The next room has platforms that work similar to the Rose Way platforms. Jump on them and they will move to the next one. Use them to easily cross the lava pit. Again there are Treasure Boxes on your way for you to collect.

The third room is an isometric version of the original Donkey Kong game. Climb up the structure while avoiding the barrels Donkey Kong throws at you, then touch him to beat this level and continue on. Your reward for completing this Action Course is the Super Slap - ignore it as the Frying Pan is even stronger.