Welcome to The Underwhere
After defeating the Brobot L-type, bring the fossilized Pure Heart to Merlon. Drive down from Flipside Tower to the second level and enter his house.
During the conversation, Dimenzio suddenly appears. He locks Mario and his friends in a magic box and explodes it.
Mario wakes up alone in a dark place. Princess Peach, Bowser, Tippi and all Pixls have disappeared. A resident tells you that you are in The Underwhere – the realm into which everyone whose game has been finished will come.
Run to the right and jump into the big well. The water restores all power points. You can use the fountain as often as you like later.
Continue to the right, use the Save Block and enter the door at the end of the path.
In the next section, you will encounter a floating girl who speaks in an unusually old-fashioned language. This is already Luvbi, even if Mario does not know her name at this time.
Continues to the right and changes to the 3D view on the large warp pipe. Behind the warp pipe leads a narrow path into the background.
Jump over the spike trap and the gaps. At the first fork, you are on the right, at the second you go to the left. Follow the long bridge until you reach the front of the section again.
At the end is a yellow block of arrows. Activate it in the 3D view and switch back to 2D. Jump over the block on the warp pipe and take the super mushroom mix there.
Then go through the door.
Across the River to Queen Jaydes
In front of you lies a wide, dark river. The ferryman offers you a crossing for four coins.
You can accept the offer or just jump into the water and swim over yourself. Stay as close as possible to the surface when swimming. The dangerous skeletal hands mainly reside in the deeper areas.
Enter the door on the other shore and walk through the palace. The D-mons there are peaceful and let you pass.
On the far right you reach the throne room of Queen Jaydes, the ruler of The Underwhere. She realizes that Mario is not really dead despite his stay in her realm.
Show her the fossilized Pure Heart. Mortimi has power over life and death and believes he can restore his lost energy.
However, the conversation is interrupted by a call. Luvbi, a young Nimbi from The Overthere, has disappeared. In addition, a strange man in green clothes was seen in the river.
Give Mortimi your help. She keeps the fossilized Pure Heart temporarily and hands you a door key for it. This opens an access to the underground waterways.
Return to the river and jump in again.
The entrance under the river
This time, let yourself sink to the bottom. Several skeleton hands try to grab you and pull you down. Stay moving and swim sideways past them.
Switches to the 3D view approximately in the middle of the river floor. In the bottom, an opening appears, which is completely hidden in 2D.
Swim into the pit and sink further down. There you will find a closed door. Open it with the key of Queen Jaydes.
In the following water room you swim first to the right and then upwards. There is a large square thwomp.
Push the block over the edge and follow it down. Then pull on the red lever on the wall. The water is drained out of the room.
Use the Thwomp and the nearby Warp Pipe as stairs. Jump to the projection on the right and destroy the wall blocks over the passage.
Return to the lever and press it again. The room is flooded again.
Swims up and through the aisle previously blocked by the blocks. Follow the waterway to the right until you face an apparent impasse.
Switch there with Mario to the 3D view. In the side wall, a hidden tunnel becomes visible. Swimming or running through it.
The Second Water Level Mystery
Follow the next section to the right end. There is another big thwomp.
Switch to the 3D view and float behind the block. Then push it over the edge and follow it down.
Drag right on the red lever to drain the water. Run to the left and use the stone and the warp pipe as platforms.
Above the lower passage is a block. Strike against it from below for a ladder to appear. It will be needed later for the return journey.
Then switch to the 3D view on the ground. To the right of the wall, another hidden passage comes to light.
Follow him up to a green warp pipe and a door. First, enter the Warp Pipe to visit an optional coin room.
In the bonus room are several rows of coins and wall blocks. Switch to the 3D view to discover additional coins behind the visible rows. Several of the lower blocks also contain additional coins.
Return through the warp pipe and now walk through the door.
Luigi makes the team complete
Let yourself fall to the right in the next room. In front of you are three large fountains.
The water jets can be used as platforms. Jump to the middle of the first well and from there quickly to the second and third. Do not stay too long, as the water current can push you down from the fountains.
Jump from the third well to the high lead on the right. Behind the great rock you hear a familiar voice.
This is where Luigi is hiding. After the attack of Dimenzio and his time as Mr. L he can hardly remember the past events.
After the conversation, Luigi permanently joins the team.
Luigi’s super jump
Luigi has the highest jumping power of all four game pieces. Hold the direction button down with him on the ground. Luigi folds up and charges his jump.
Then release the button to make a huge super jump. This allows you to reach particularly high platforms and attack enemies over you.
After the conversation, switch back to Mario and switch to the 3D view on the lead. Behind the rock lies a hidden long-term mix. This gradually restores force points over a longer period of time.
Then drop to the left of the projection and switch to 3D again. Below the entrance is a hidden niche with a chest.
Open it and take the Dry Bones card No. 029 to you. This will cause double damage to all Dry Bones in the future.
Now switch to Luigi and use his super jump to get back to the high door.
Back to the surface
Go through the door and return to the previous water room. Use the prepared ladder and press the lever again so that the room is flooded again.
Swim back through the waterways and leave the underground facility through the door at the bottom of the river.
Get out of the water on the left side of the river and walk through the door back to the long area where you met Luvbi at the beginning.
Go all the way to the left. There are several high tubes that Mario could not overcome before.
Switch to Luigi and use his super jumps to get to the first warp pipe and then to the higher level.
Now jump from Warp Pipe to Warp Pipe to the right. Alternatively, you can switch to the 3D view with Mario in between and bypass some obstacles laterally.
In one of the question mark blocks is a Happy Flower, which rains coins from the sky for a short time.
At the end of the upper path you reach a green warp pipe. Get in and get into the background of the section.
Optional: The Princess Peach (3) card
In the background you will find two more tubes. First descends into the left warp pipe and then uses the warp pipe on the right.
In the underground space hovers a single opponent. Defeat him with a jump or Luigi’s super jump.
After the victory, a chest appears. Open it and take the Princess Peach (3) card No. 225 to you. She shows Princess Peach with her short, sporty haircut.
Then returns to the upper path through the two tubes.
Now go through the door next to the warp pipe, via which you entered the background.
Finally found: Luvbi
In the next room you can hear someone singing from a distance. Run to the right and use Mario to switch to the 3D view.
This allows you to walk laterally past the high tubes, which block your path in the normal view.
At the end of the corridor you will find the floating girl from the beginning of the chapter. It is actually the wanted Luvbi.
She believes she is waiting for a particularly attractive prince and shows little enthusiasm about Mario and Luigi.
Luvbi asks for proof that you have indeed sought it. She asks you her name. Choose the right answer:
Luvbi
After you give her name, she realizes that Queen Jaydes has sent you. She then independently flies back to the palace.
You must also return to Queen Jaydes. Run through the previous sections, cross the river and re-enter her throne room.
The fossilized Pure Heart awakens
Luvbi is already waiting for Queen Jaydes. After a short and less serious apology, the Queen thanks Mario and Luigi.
Mortimi uses her power over life and death to revive the fossilized Pure Heart. His paint and energy return completely.
You will receive the revitalized Pure Heart.
Queen Jaydes also explains that Mario and Luigi did not really die. Dimenzio just magically sent her to The Underwhere.
Choose the answer that you want to return to Flipside. Mortimi then opens a portal and sends both brothers back to the world of the living.
In Flipside, you’ll meet Merlon and Tippi again. All Pixl will also return to your team. Princess Peach and Bowser have disappeared.
This concludes the section in The Underwhere. Next, in Flopside, you have to find the seventh Heart Pillar and use the revived Pure Heart.