After our heroes entered the time machine, they ended up back in the present day of the Mushroom Kingdom. But they couldn't find King Shroob or Commander Shroob anywhere.
Lemmy: Where did he go?
Boo: I don't know, Lemmy. But this place is in ruins.
Boo was right: the houses were broken down, the street was full of fainted Toads, and they looked ahead and saw that Castle Koopa was destroyed.
Lemmy and Iggy: NO!
They all ran to the castle only to see Ludwig on the ground, fainted.
Lemmy: Ludwig, wake up!
Ludwig wouldn't wake up, so Lemmy slapped him, then he woke up.
Ludwig: Huh? Oh, Lemmy and Iggy.
Dimentio: What has happened here?
Ludwig: Well, it all started when Commander Shroob and some other Shroob came to the Mushroom Kingdom and started wrecking the place. Then they came to our castle and started destroying the castle. I am the only survivor, the others... were taken away.
Dry Boners: Do you happen to know where?
Ludwig: Yeah, he took them to... Planet Shroob.
Shroob Fighters: WHAT?!
Lemmy: How are we going to get to there?
Iggy then spotted something.
Iggy: We could always try using the Clown Copter.
They all looked where Iggy was pointing.
Boo: There's three of them.
Lemmy: That will be fine. Me and Iggy can share one, Dimentio can have his own, and Boo and Dry Bones can share.
Boo: Then letís get going so we can kick some Shroob butt!
They all jumped into the Clown Copters and found some fishbowls lying around the kingdom. They figured they could use those as space helmets so they could breathe. Then they ventured off into deep space, looking for the planet.
Dimentio: I can't seem to find it anywhere.
Lemmy: Well keep looking, we have to fi... Hey, I found it!
They all looked where Lemmy was pointing and saw a big, purple planet shaped like a mushroom.
Boo: Come on.
They all landed on the planet to find a bigger castle, bigger than the last time Lemmy, Iggy, and Dimentio were here. They entered the castle and walked through a hallway. Then they found the throne room, where they saw Commander Shroob and King Shroob with the other Koopalings.
King Shroob: What should I do with these Koopas? Do you have any idea, Commander.
Commander Shroob: I could think of 100 things to do with them. But what I am thinking right now is that we should shroobify them once more!
Larry: Not that again.
Commander Shroob: Yes again, and there is no one to save you this time.
Boo: Think again!
Commander Shroob: What?! Who said that?
Boo: No one, except for my fist!
Then Boo punched him while he was still invisible.
Boo: Take this!
Boo threw another punch at Commander Shroob.
Commander Shroob: Who keeps punching me?!
Boo then appeared.
Commander Shroob: You! Then that means...
Lemmy: We are here as well.
Commander Shroob: How did you know we were here?
Iggy: Because you left without Ludwig!
Commander Shroob: I thought we forgot something. But it doesn't matter, because you cannot defeat King Shroob!
King Shroob: TASTE MY WRATH!
King Shroob threw beams of light at our heroes, but Boo used his powers to turn everyone invisible. Dry Bones started throwing bones at King Shroob, but King Shroob busted them and turned them into dust with his hands. Lemmy used his Freeze Gun to freeze him, and it worked. Dimentio and Iggy started shooting magical beams and wand beams at King Shroob. Then King Shroob broke out of the ice and started attacking with a fast ray gun, but our Shroob Fighters were fast enough to dodge them all. Boo turned invisible and started to punch the king many times, then Dry Bones, Lemmy, Iggy, and Dimentio threw bones, wand beams, and magical blasts at King Shroob while he was distracted by Boo's punches. Then Boo and Dry Bones used the Bowling Boo move to finish King Shroob off. But Dry Bones threw Boo so hard into King Shroob that King Shroob got shot back and he hit Commander Shroob. Then they both crashed into a wall and fainted. But some purple stuff came out off Commander Shroob.
Lemmy: What is that purple stuff?
Iggy: It kinda looks like... Uh oh.
Boo: What, what does uh oh mean?
Iggy: I have seen this stuff before, and that purple stuff is the soul of the evil witch soul known as Cackletta!
Dry Bones: That does not sound good.
Then the purple stuff formed into Cackletta's soul.
Cackletta Soul: Now that you know, I must tell you that Commander Shroob hasn't been getting revenge on you, it is I who has.
Cackletta Soul: Yes, you see, the first time you beat this Shroob, I wasn't involved with this, but the second and third times, I was. I did this because I wanted to get rid of the Mario Bros. But I needed to get rid of anyone who also hated them. So I possessed Commander Shroob because I wanted a body that had an army and a good mind.
Lemmy: So all those times we were fighting Commander Shroob it wasn't him, but was...
Cackletta Soul: Me! Now that you know, you must be eliminated so I can have no one in my way of destroying the Mario Bros! This also goes for your friend Boo and Dry Bones too!
Cackletta's soul started to make her eyes glow so she could fire a laser. Then the laser fired.
Find out what happens to our heroes in part 5.