Mario quickly ran towards his brother to see if he was okay. Although he was extremely injured and in need of some serious medical attention, Mario was incredibly relieved to see him alive.

"Hey, bro… You did it… You really kicked Bowser's ass just now…", Luigi told his brother.

"Luigi! You're still alive!"

"I guess Bowser wasn't strong enough to kill me after all…"

"Luigi! I won't let you die! I'm going to get you out of here alive and well!"

"Mario… Please, listen… I want you to move on without me…"

"What?! Luigi, don't say that! I'm going to get you out of here! Why won't you believe me?!"

"Mario… The castle will go up in flames in just ten minutes… The power of the pyro flower has already worn off… If you try to get me out of here, we'll both die, and you know that…"

"Luigi, I can't leave you behind… I'll never forgive myself if I do…"

"Mario… One day, many years ago, I made a promise to myself… I told myself that if you would ever be in grave danger, I would protect you with my life… Unfortunately, I was never able to keep that promise… I was always the one who dragged you into danger… But you were always there to help me, Mario! You have never once failed me in my entire life… But I always failed you… Until now… You have been the best brother I could have wished for, Mario… I'm glad it I'm the one who sacrificed myself for you, and not the other way around…"

"Luigi…"

Mario shed a tear.

"You've been a great brother to me too, Luigi. Much greater than you can ever imagine. If I've led you to believe otherwise, I'm sorry…"

"I'm glad to hear that, Mario…"

There was a short silence.

"It's time to say goodbye, Mario… The castle will be destroyed in a few minutes… Please flee the castle without me… It's better that way…"

"Okay, Luigi. I will. I won't disappoint you…"

"Now go, Mario! Go and live the rest of your life in peace!"

Mario slowly walked away from Luigi.

"Goodbye, Mario…"

"Goodbye, Luigi…"

Mario started running as fast as he could. He looked back one final time before making his leave.

"Goodbye, world…"

Luigi was killed by the lava flood in Bowser's castle.

Mario had five minutes to escape from the now burning castle before it went up in flames entirely. Another evacuation sound played.

"Warning! The castle will be flooded with lava in five minutes! All Koopas must evacuate immediately!"

Mario swiftly jumped from one platform to the other. The platforms felt strangely empty now that there were no Koopas that stood in Mario's way. As Mario kept running, parts of the castle started falling apart. Lava flooded entire sections of the castle. While most Koopas were able to evacuate in time, some weren't able to make it and were burned in the flood. And all because Bowser wanted Mario dead.

"I'm afraid I can't let you leave, Mario!"

Two Koopas walked up to Mario and blocked his path.

"As loyal servants of king Bowser, we must destroy you!", the second Koopa said.

The Koopas angered Mario. He quickly grabbed one of the Koopas and broke his back.

"HOLY SHIT!", the other Koopa yelled.

Mario threw the injured Koopa off of the platform, presumably killing him.

"OKAY, OKAY! I'll leave! I'll let you pass!"

The Koopa quickly made his leave.

"Coward."

The exit wasn't far away. Mario kept running. One last warning sound played.

"Warning! The castle will be flooded with lava in one minute! All Koopas must evacuate immediately!"

When Mario arrived at the exit, it was way too crowded to even attempt to leave the castle. Mario decided to take action to ensure his own safety.

"GET OUT OF THE WAY IF YOU DON'T WANT TO DIE!"

Bowser's minions made room for Mario. Many cowered in fear at the mere sight of him. As soon as Mario was a considerable distance away from the castle, he stopped running to catch his breath.

BOOM!

Bowser's castle exploded. Thousands of bricks were launched into the air. Hundreds of body's were catapulted away. Mario saw it all happen. As the remains of the castle slowly burned away, Mario fell on his knees, crying.

"The great king Bowser… Killed by Mario… I can't believe it…"

"Mario may have won the battle, but Bowser has won the war. Remember, he still destroyed the entire Mushroom Kingdom, killed Peach AND Luigi. I don't think we'll ever see anything of Mario again."

"But giving up your life for the grand scheme of things? That takes dedication, man."

"There's just one thing I wonder…"

"What's that?"

"How are we going to tell Junior? He's going to be devastated."

"Ask Kamek to tell him. He's good with the kid."

Hundreds of Koopas marched through the hallway, following Kamek to Bowser Jr.'s room.

"Stop."

The Koopas stopped moving.

"I'll take it from here. Junior isn't exactly trusting of many people besides me."

Kamek knocked on Bowser Jr.'s door.

"Junior? Are you in there? I've got something important to tell you."

Bowser Jr. opened the door.

"Go away, Kamek! I'm watching TV!"

"Sit down, Junior. There's some very bad news I've got to tell you."

"Are we out of candy?!"

"Worse."

"What could possibly be worse than being out of candy? Did the TV break?!"

"…"

The Koopas that were standing outside heard uncontrollable crying coming from Bowser Jr.'s room. For minutes on end, all they could hear was crying.

"Geez, he isn't taking the news too well.", one of the Koopas said.

"How did you react when you heard that your father died? Besides, how old is the kid? Like, eight? Give him a break."

Silence. Bowser Jr. was sitting on his bed, thinking about what Kamek told him.

"Who did this?", Bowser Jr. asked.

"What?"

"Who killed my father, Kamek?"

"Who do you think? Mario, of course."

Bowser Jr. became angry. Very angry.

"I will come for you, Mario! And when I find you, I'LL MAKE SURE YOU WON'T LIVE TO SEE ANOTHER DAY!"

Meanwhile, in a nearby city…

"Hey, bro!"

"What is it?"

"Have you heard the news?"

"No. What's wrong?"

"The entire Mushroom Kingdom has been destroyed by Bowser! All of the Toads are dead! And so is Peach! And do you wanna know somethin' else?"

"Of course!"

"Mario and Luigi are presumed dead as well! Bowser won!"

"Mario and Luigi?! DEAD?! That's certainly newsworthy!"

The two men, who were sitting on their couch with a pizza and some soda, watched some TV for a few minutes. They wanted to avoid talking about the big news. After a while, one of them started talking.

"You know, I feel kinda bad for treating them so poorly now."

"How were we supposed to know this was gonna happen? Besides, it's not our fault that they died."

"If only we could have done something to prevent it from all happening…"

"What's done is done. You can't change the past. Let's just move on with our lives and never talk about this again, okay?"

"Okay."

Meanwhile, somewhere far away from the Mushroom Kingdom…

"Grandpa?"

"How many times have I told you to not come in here without knocking?"

"I think I have the right to come in here without knocking. Especially with the importance-factor of the news I'm about to tell you."

"Well then, go ahead."

"The entire Mushroom Kingdom has been destroyed by Bowser, recently. Everyone is dead. That includes Mario, Luigi and Peach."

"So you're telling me that Bowser had a plan that actually worked? That he managed to wipe out the entire Mushroom Kingdom? What kind of nonsense is that?!"

"We have TV these days, you know. Also, I'm not the only one who knows about this. I heard it from someone else."

"Truly? I can't say I feel bad for them, after the whole conflict I had with Mario."

"You're the one who started that conflict in the first place! There's no reasonable conversation to ever have with you. I'm out of here. If only I could've changed this…"

4 months later…

Ever since the doomsday, Mario had been wandering aimlessly around the remains of the Mushroom Kingdom. He thought about the people that he had failed, ways he could've prevented the doomsday from happening in the first place, and, of course, his future.

"How long has it been since the doomsday? I really don't know. Ever since the destruction of Bowser's castle, all I've done is wander in circles, it seems. The only food that I have is some Koopa meat that I managed to gather close to the remains of Bowser's castle. I'm not sure how much longer I'll be able to survive with this amount of food. Thank god there's still plenty of water around here."

Mario sat down and built a small camp. He roasted some Koopa meat above the campfire.

"I had it all. I was about to become the prince of the Mushroom Kingdom. I had a great brother. Not to mention the amount of friends I had, or the amount of people who admired me. But I just had to blow it, didn't I?!

Mario ate the Koopa meat.

"Every now and then I try to tell myself that it wasn't my fault. But whenever I do, deep down, I know that I'm lying. It was because of my terrible plan that everyone died. It was because of my poor fighting techniques that Peach and Luigi died. And let's not forget Yoshi, who died because I just didn't act quickly enough."

Mario kept staring at the fire for a while.

"I wonder… Will I ever become a hero again? Will I ever find another place where there's a princess I can save? One where there's an entire race of people who look up to me? No. I probably won't."

Mario reached inside his pocket. He found a picture that had been taken many years back.

"Maybe one day I will find peace inside my head. That day will be a long time from now. Until then, I guess I'm destined to just wander around the world, searching for that inner peace."

Mario looked at the picture. It was a group-photo of Mario and his friends. Everyone was on it; Mario himself, some friends he made during karting, golfing and partying, Yoshi, Toadsworth, Peach, and last but not least, his brother, Luigi.

"Goodbye, everyone…"

Mario slept well that night. When he was about to make his leave, Mario took one last look at the picture. He buried the picture deep in the ground where the campfire had been, leaving behind his last memory of the Mushroom Kingdom.

The end

To be continued in Super Mario Doomsday 2!