Mario and Co. are seen entering Starborn Valley. After going through the sewer and the harsh environment, they need a rest. They knock on Merle's door and Merle answers. He invites them in and they gather around the fire. Merlon enters the room.
Merlon: So, how did it go?
Mario holds up the two Crystal Hearts he acquired from Johnny and Tubba Blubba.
Merlon: Excellent! Now, I have good news. I have found the guardian of the next one.
Mallow: Really? Who is the guardian?
Merlon: I believe it is a young fellow named... well... I can't remember his name, but, I found the location. He is somewhere in Boo Woods.
Merlon: Calm down; not near King Boo's old mansion, but somewhere near your mansion. Also, I found out more of the prophecy. It says that the Evil King will eventually leave the group to save his dwelling, but a new member will join the group, and that is the Evil Prince.
Mario: Evil Prince? I wonder... no. Anyway, so, the next piece is in Boo Woods. Letís-a go!
Luigi: But Mario, we have to pass through the Mushboo Kingdom to get there, and we all know King Boo is going to get us!
Mallow: Hey, why don't we call Bowser and see if he can give us a ride?
Geno: Good idea, Mallow. Merlon, do you still have Bowser's number?
Merlon: Of course I do.
Merlon rushes off to get the number.
A Duplighost is seen floating Indian style outside Luigi's Mansion. This Duplighost wears a black sheet, a white head band, and white shoes with black soles, and has white eyes. Right now, the Duplighost's eyes are shut, and he is talking to himself.
Duplighost: Come on... come on...
The Duplighost stops floating and lands on his feet.
Duplighost: Darn it. I can't feel any of Ying's energy. I don't understand why, though. I have been searching for a long time, why can't I feel anything?
Then, a Boo comes out and yells for someone.
Boo: SHY GUY! SHY GUY! WHERE ARE YOU?
The Duplighost gets a shocked face. He then uses his ability and transforms into a Shy Guy. He runs toward the Boo while keeping his mind on other things.
Duplighost (while a Shy Guy): I can't tell this nice Boo about who I really am, or tell him that the Shy Guy he knows doesn't exist. And if I were to show him who I really am, I still can't let him help due to the fact that even if I find my sister, the journey to finding her could be dangerous and he hasn't shown any fighting experience. I couldn't let him get hurt.
He eventually reaches the Boo.
Shy Guy: Sorry Booser, what are you haller'n about?
Booser: I called because I just have a strange feeling that I am supposed to give the Mario Bros. this Crystal Heart I found long before I joined King Boo's army back when I was evil. Anyway, I also thought it would be nice to see the Marios again.
Shy Guy: Oh, okay.
Booser and Shy Guy are about to head inside to wait for Mario and Co. to come to the mansion and get the Crystal Heart, but justthen, they hear a scream. They look around and see nothing. Then, they hear it again and look up. They see a Koopa shell with spikes coming down toward them. They jump out of the way and the shell lands with a thud. Booser and Shy Guy approach it and look at each other.
Booser: What is it?
Shy Guy: I don't know.
Then, they see an airship that looks like a Koopa.
King Boo: You two have failed me for the LAST time!
Booario: We're deeply sorry, King Boo.
Booigi: Yeah, I thought inventions made by Prof. Boo would give us an edge... but I guess I thought wrong.
King Boo: OF COURSE YOU THOUGHT WRONG!
King Boo is actually turning red and beginning to steam. Princess Boo then approaches him.
Princess Boo: Sweety, calm down.
King Boo turns white again and stops steaming.
King Boo: ... All right, I'm calm.
Then the doors open and a Boo with sunglasses floats in.
Boo with sunglasses: Yo man, I got what you needed. I got a Crystal Heart right here!
The Boo shows King Boo a light blue Crystal Heart. King Boo gets wide-eyed and does a series of flips and spins in the air.
King Boo: YES! WE FINALLY HAVE A CRYSTAL HEART!
King Boo takes the Heart from the Boo.
Boo with sunglasses: Yo man, could I get back to Club Boo so I can give the Boos music?
King Boo: Oh, sure DJ Boo. Go on ahead.
DJ Boo: Thanks man.
DJ Boo leaves and Booario and Booigi are left astonished.
Boo Bros: HOW?!
King Boo: After you left, I tried to locate another Crystal Heart. I was able to find one in Marrymore. So, since you two were gone and Booster is at Bowser's Keep, I sent the third best Boo: DJ Boo. And since those Mario Bros. would not be able to interfere, it was very simple for DJ Boo. Now, you two get back to the Mario Brosí house and try to do BETTER!
Booario and Booigi leave the room with gloomy looks on their face.
King Boo: That leaves only five more left. I have to send troops out to find the next one. But DJ Boo went back to Club Boo. Hmmm... I don't know who to send, but I can at least stall the Mario Bros. while I think of someone to send.
From around the corner, a Boo Guy with a sword sash is listening in on King Boo.
Boo Guy: This is my chance.
The Boo Guy emerges from the corner.
Boo Guy: King Boo, a couple of troops and I could go hunt down the Mario Bros. and stall them.
King Boo: You're the new recruit. Hmmm... All right, and if you could, try to kill them!
Boo Guy: Will do, sir!
The Boo Guy rushes off, but is stopped.
King Boo: Hold it! You don't even know where to look.
He turns to Princess Boo.
King Boo: Do you have any ideas?
Princess Boo: Maybe, we can use our combined powers and try to locate them.
King Boo: It's worth a shot.
King Boo grabs Princess Boo's hand and they begin to search for the Mario Bros. Eventually an image appears above them. Mario and Co. are seen on the Koopa Cruiser heading for Luigi's Mansion. King Boo then gets an angry look on his face and lets go of Princess Boo's hand.
King Boo: Booser! I can't believe that traitor had a Crystal Heart this whole time!
Boo Guy: Luigi's Mansion. I'll gather the troops and have the Mario Bros. killed, along with some Crystal Hearts added to our collection.
The Boo Guy rushes off to gather troops, while King Boo laughs evilly.
Mario: You mean Booster took over the Keep?!
Kamek: Yeah. We were able to take out his troops, but Bowser when tried to attack him, Booster defeated him and sent Jr. flying. So, I went after Jr., and he ended up landing at Luigi's Mansion. I explained everything that was happening to Booser and Shy Guy. They have the Crystal Heart for you. And once we are done there, we will head for Crystal Heart number four.
Mallow: Hey Mario, didn't Merlon say that someone new would be joining us? Like an Evil Prince?
Luigi: Mallow's right. Maybe Bowser Jr. is the new member.
Geno: He could be. But we have to hurry, King Boo's troops could try to attack the Mansion.
Kamek: Don't worry, we're not too far.
Eventually, they make it to the Mansion. The Cruiser lands and Mario and Co. head for the Mansion. They knock and Booser answers. Booser directs them to the backyard, which is not a graveyard anymore but rather a nice little area with a pool, BBQ, and a deck. Shy Guy is seen at the grill, and Bowser Jr. is seen eating a hamburger. Little scrapes can be seen on him here and there, but he is at full health and happily eating.
Shy Guy: Mario, nice to see you and your brother again, along with some friends. Care for a hamburger?
Mario: No thanks, Shy Guy, we are in a hurry.
Shy Guy: Ah yes. The Crystal Hearts. Well Booser, youíd better go fetch the Heart.
Booser: Oh, right. I'll be right back.
Booser heads inside to get the Heart. Just as he is gone, Luigi looks over the horizon and sees something coming their way.
Luigi: What is that?
The others look to see what Luigi is pointing at. Mario squints and sees a Boo Guy holding a sword and commanding Boos and other Boo-like enemies to attack the Mansion. They then start to charge.
Mario: Crud. Looks like we're going to do some fighting! Ready, guys?
Shy Guy: Ready.
Mario: You guys want to help?
Shy Guy: Yeah.
Jr: I want to show those Boos who's boss!
Kamek: I'll help too! Ready, troops?
Koopatrols, Lakitus, and Hammer Bros. pile out of the cruiser.
Booser comes out, surprised to see the troops.
Shy Guy: King Boo's troops are attacking.
Booser: Ah. I might as well help.
Mario: Okay, men... CHARGE!
The two groups charge toward each other and a big fight breaks out.
BOSS BATTLE: King Boo's Troops
Mario pulls out his hammer and charges toward a group of Dry Bones. They start throwing bones at him, but Mario whacks them away and reaches the Dry Bones. He then starts smacking them with his hammer until they have fallen to little pieces. From behind, a couple Boos and Lakiboos start shooting lightning bolts and Spiny Shells. Mario is sent to the ground and is being pelted. Then, Jr. runs up and smacks the Boos and Lakiboos with his magic paintbrush, leaving them colorful. Jr. then blows fire and they start burning and rush off. Jr. helps Mario up and they high-five.
Luigi is seen with Booser and Shy Guy, and they are surrounded by Boos, Dry Bones, and Boo Guys. Luigi pulls out his hammer and spins around, swinging his hammer and taking out a quarter of the troops surrounding them. Booser inhales, then exhales a stream of orange fire, not red like Booario's. It takes out more troops. Shy Guy then jumps to avoid a headbutt from the rest of the troops. He then reaches into his robe and throws shuriken at the remaining troops. The Boos poof away and the Dry Bones burst into pieces.
Booser: Wow, I didn't know you could do that.
Shy Guy: Well, I... AHH!
Shy Guy looks above and sees a Lakiboo with a bomb. He drops it, and Shy Guy is hit. He is sent out of the fight and knocked out. Booser then fires a stream of fire at the Lakiboo, who is laughing. He is hit and falls off his cloud, burnt. Booser and Luigi rush to Shy Guy's aid.
Mallow and Geno are seen firing stars and soundwaves from the Sonic Symbols at the Boos. The Boo Guys swiftly dodge the stars, but are caught by the soundwaves of the Symbols. Spear Guy ghosts come in and stab Mallow and Geno. They endure the hits, and Mallow uses Shooting Star. Bunches of stars fall only in the area of the Spear Guys, and Geno finishes with Geno Flash. He turns into a cannon and fires a mini sun that explodes on the Spear Guy ghosts. Geno and Mallow high-five.
Kamek is seen with the Koopa Troop firing spells, Spiny shells, and hammers at King Boo's troops. The Koopatrols charge head-first into the Boos, who disappear when sent to the ground. Kamek shoots a fire spell that ignites all Boo Guys, and the Lakitus and Hammer Bros. wipe out the other troops.
Kamek: Piece of cake.
Then the Boo Guy with a sword charges toward Kamek and almost slashes him. Kamek fires an ice spell to try to freeze him. The Boo Guy turns invisible and charges toward Kamek, knocking him off his broom. While Kamek struggles to get back up, the Boo Guy points his sword at him. The sword he is using looks exactly like Meta Knightís, but has a white gem on it whereas Meta Knight's has a red gem.
Boo Guy: I only want one thing. Take me to Mario!
Kamek: ... Okay?
Kamek gets up and takes him to Mario, who is seen with Jr. looking around for more fights.
Kamek: Mario. This Boo Guy wanted to talk to you.
The Boo Guy approaches Mario and signals him to come to where he can whisper in his ear. Mario does so.
Boo Guy: Meet me at Club Boo in the Mushboo Kingdom. I have something important to tell you.
The Boo Guy then turns to his troops.
Boo Guy: LETíS GET OUTTA HERE!
The leftover troops who hadnít disappeared get up and rush back to the Kingdom.
Mario: That was odd.
Luigi: Mario! Come quick, it's Shy Guy.
nsert SMRPG Trouble here*
Everyone is gathered around Shy Guy. Shy Guy is motionless. Booser turns to Kamek.
Booser: Isn't there anything you can do?
Kamek: Well, I'll try,
Kamek fires a spell at him. He then turns into a Goomba, and is still motionless.
Kamek fires again; this time, Shy Guy turns into a Koopa.
Kamek: Hey, I'm getting old! I sometimes forget spells.
Kamek fires again, this time turning him back into Shy Guy.
Kamek: Wait, this isn't right.
Luigi: What's-a wrong?
Kamek: My wand readings say I turned him into a Duplighost, but why did he turn back into Shy Guy?
Everyone looks at the unconcsious Shy Guy, who slowly begins to wake up.
Shy Guy: What happened?
Booser: You were hit by a Lakiboo's bomb. We took care of the troops. Now, tell me this. You can fire shuriken, and when Kamek was trying to heal you, he turned you into other things, but the last one was a Duplighost. But you turned back into a Shy Guy. Care to explain?
Shy Guy looks at everyone, and sighs.
Shy Guy: All right. Booser, I am not a Shy Guy. The truth is...
A puff of smoke appears around him, and in Shy Guy's place is a black Duplighost.
Duplighost: I am a Duplighost with the secret identity as a Shy Guy. When we played tennis together, that was me. My real name is Yang Duplighost. I have been hunting down my sister for years. Her name is Ying, and we are ninjas, very powerful ones.
Everyone is astonished at this. Booser then pipes up.
Booser: But why didn't you tell me the truth?
Yang: You never really showed any fighting experience. If I told you, you would've wanted to help me, but I couldn't let you get hurt. You have been so nice to me and if you got hurt, I couldn't live with myself...
Booser: It's okay, Shy Gu... I mean, Yang. I don't blame you for doing that. If you hadn't shown any fighting experience, I wouldn't have told you either. Yang, you are my best friend, and I'm glad you were looking out for me.
Yang: Thanks, Booser.
Jr: Okay, this is very touching, but we have other things to take care of. What did that one Boo Guy say to you, Mario?
Mario: He told me to meet him at Club Boo in the Mushboo Kingdom. But if me, Luigi, you, or Kamek go in, we will get beaten, badly.
Booser: Hey, what if we go, Mario?
Mario: Oh... well...
Yang: Yeah, it's perfect. We are both ghost-like, so we should be fine.
Mario: I'm not worried about you, Yang. King Boo has never seen you before. It's Booser I'm worried about. He's a traitor to King Boo's army. If he goes in, he will get beaten.
Booser: Not if I go incognito. Kamek, can you help?
Kamek: I'll do my best.
He fires a spell, and Booser gets hit. Then, glasses with a big nose and bushy mustache appear on Booser.
All but Booser: -_-
Booser: Come on, Yang, letís go.
Both disappear, but Booser comes back.
Booser: Just wait for us here, and we'll bring the message back to you.
He disappears and reappears in the Mushboo Kingdom entrance, along with Yang.
Yang: Okay, letís go.
They approach the gate but are stopped by a Security Boo.
Security Boo: Hey, who are you supposed to be?
Booser: We are travelers trying to seek some shelter. We have been traveling for weeks, and are very tired.
Security Boo: Well... all right. I'll let you through. A piece of advice, try going to Club Boo. I hear it is amazing.
Yang: Will do.
Booser and Yang enter the town, and the gate shuts behind them. They look around and see a sign. They approach it and it shows directions to Club Boo.
Booser: Boo Town Harbor, west of here. Letís go.
They head west and eventually make it to the harbor. They look around and see a building with a sign that says "Club Boo" in neon letters. They head inside and look around. It looks like a diner for Boos. There is a bar with a TV showing a football game, and tables with Boos sitting at them and being served by Boos in bow-ties. Booser looks around and sees a private area with only one Boo, a Boo Guy. They nod and head to him.
Booser: Excuse me, but are you by any chance the one who wanted to see Mario?
Boo Guy: Yeah, but you're not him.
Yang: He sent us because he knew he wouldn't be able to get in.
Boo Guy: How well do you know him?
Booser: Well, I know his brother, and he tells me stories about him all the time.
Yang: As do I.
Boo Guy: Okay. Listen up. King Boo has acquired a Crystal Heart.
Booser: That's impossible. He sent Booario and Booigi to the location of the third Crystal Heart. And Booster has Bowser's Keep taken over.
Boo Guy: Yes, but, there is one more Boo who almost has the same rank as those three. His name is DJ Boo. He's the DJ here, and he is powerful.
Yang: Okay, so, why are you telling us this?
Boo Guy: The truth is, I am a new recruit, or so King Boo thinks. I am actually undercover, looking out for the Mario Bros.
Boo Guy: Because... Okay, please take off those glasses, I can't take you seriously. Why are you wearing that anyway?
Booser (while taking the glasses off): I am a traitor of King Boo's army. Me, Luigi, and a couple others took King Boo out a little while back. That's how I know Luigi.
Boo Guy: Right. Anyway, I am looking out for them because I am trying to see if they have the power to take on an enemy that has intense power and... is imprisoned within the two darkest objects.
Yang: Two darkest objects...?
Then a Boo waiter comes in.
Boo: Would you like to... to...
He is staring at Booser.
Boo: BOOSER! YOU TRAITOR! DJ BOO, WE HAVE A SERIOUS PROBLEM!
A Boo with sunglasses is seen floating in.
DJ Boo: What is going... oh.
He is looking at Booser.
DJ Boo: I'll take care of them. You go and get King Boo.
The Boo nods and leaves.
DJ Boo: The three of you are in for a world full of hurt.
He whistles and three Boos come in and grab Booser, Yang, and the Boo Guy. They take them to the stage where DJ Boo does his work. DJ Boo then appears at a somewhat tall stand with his DJ equipment. He then grabs a microphone.
DJ Boo: ATTENTION ALL BOOS! TONIGHT, I HAVE AN AMAZING SHOW FOR YOU! A FIGHT, BETWEEN ME AND THAT TRAITOR BOOSER, HIS FRIEND, AND ANOTHER TRAITOR!
All the Boos cheer and DJ Boo puts the microphone down and presses a button. His stand starts to grow legs and lift itself up. From the sides, two claws appear. Booser, Yang, and Boo Guy get anime sweatdrops.
DJ Boo: Get ready to... ROCK!