(This was written in 2015 and edited in the span of an hour.)

It did freak Jimmy out when he gained control over his counterpart Johnny Ghost and couldn't remember how he did it. He sat up, the familiar feelings of Johnny Ghost's eyes changing into Jimmy Casket's being largely ignored.

The now red eyes swept around the moderately sized cave.

"What have you gotten us into this time Johnny-Boy?" he mused to the unconscious other half of their soul.

Jimmy hoisted himself off of the yellow flowers he was laying on, trying to remember how he got in that situation. He looked around, trying to find his knife, Knifey. As he looked, the memories leading up to his current situation came back

Apparently Johnny was running from his name sake, that being a ghost, and didn't notice the hole, hitting his head on the way down. Jimmy would definitely be in control for a while. Although, Jimmy didn't see the upside to being in control with no one to brutally slaughter with the found Knifey.

The hole above the cave gave light to the carved arch leading into a tunnel to his left. Even with Jimmy's strong legs he doubted he could jump up high enough to climb out the hole. He moved through the tunnel, stuffing his hands, and Knifey, into Johnny's hoodie pocket.

After some walking, a voice spoke up, "Howdy! My name's Flowey!"

Jimmy looked around for the source of the voice that sounded something like his, a small smile on his face. Maybe there was someone to kill.

"Down here," said the yellow flower with a friendly face in front of him.

The smile he wore fell off, but he had seen weirder things so Jimmy didn't question it. "My name's Jimmy!"

"You're new here aren't you?" Flowey asked and didn't wait for a reply, "Let me show you how things work around here!"

The surrounding area turned black and a video game like menu appeared showing a yellow bar with HP 30/30 and LV 1. Above that was a white lined box with a cartoon heart cracked down the middle, one side red, the other blue.

"That heart is your soul," Flowey explained, "It starts off weak, but can grow stronger with lots of LV!"

It was simple to move his soul, just like moving a third arm or moving Johnny while he was in control.

"That stands for level right," Jimmy asked. He might as well play along and kill the flower later.

"No, it stands for LOVE silly. You want some LOVE don't you?"

That didn't inspire fuzzies, especially since Jimmy knew that tone.

"I may be dumb, but I'm not stupid Flowey…" Jimmy gripped Knifey's handle in his pocket. "I use that same tone when I want to tell someone my secret!"

Flowey looked shocked for a second, before his face morphed into a demon's face.

"Well then, Die!"

A bunch of little white seeds circled the soul in the box, slowly moving closer. Flowey laughed, Jimmy smiled, pulling out Knifey.

Until the seeds disappeared.

There was an awkward silence between the two killers before a fireball appeared and threw Flowey into the shadows of the now restored cave.

An anthropomorphic goat woman walked over, "What a horrible creature, torturing such a poor, innocent youth."

"I'm not young." Jimmy said, offended, "I'm 28!"

"Oh, I'm sorry then. All the humans that have fallen have been children. I'm Toriel, caretaker of the ruins," Toriel extended a hand in greeting.

Jimmy gave a dismissive wave with the hand not holding Knifey, which was back in the pocket, "Yeah, yeah. I'm Jimmy."

He would have gone ahead and killed her already, she stole his kill, but he didn't want to get the same treatment as the flower, assuming that she was the origin of that fireball. A surprise attack would be more fun anyway.

Toriel frowned retracting her hand, "Well, come with me. I shall show you through the Ruins."

She walked off and Jimmy followed, realizing that she was basically his tutorial.

He hoped that there were others to kill, only two people does not a slaughter make.

When they stepped into the Ruins, Jimmy's first thought was Ack! The purple! Everything was purple. The only things not purple were a pile of red leaves and a glowing yellow star thing above it.

He quickly followed Toriel into the next room to get away from the purple, but everything was still purple.

"In the Ruins there are many puzzles. Ancient fusions between distractions and door keys," said Toriel.

She then walked a specific pattern on purplish grey buttons on the floor, opening the purple door on the other side of the room.

"Let us continue."

Jimmy followed Toriel into the next room, staying quiet. He'll get a chance to kill her when she wasn't needed to solve the puzzles, he couldn't read the signs after all.

Toriel started to say something, probably treating him like a kid, before stopping and reconsidering what she was going to say. "I will let you solve this one. The answer is marked," she gestured to three switches on the left wall.

She wasn't kidding about being marked, the two out of three switches Jimmy guessed were correct, had so many arrows pointing to them even a baby could solve it.

He rolled his eyes and flipped the switches, "They don't need to be that marked," he muttered.

They moved into the next room, which had one of those punching bag dummies in it. "As a human in the underground, monsters may attack you, and you will enter a fight. Strike up a friendly conversation, stall for time and I will come resolve the conflict."

He stepped closer to the dummy and the black shroud re-appeared. Buttons labeled Fight, Act, Item, and Mercy were now below the previous bar and his soul was over the Fight button.

He moved his soul to the Item button and pressed it. A menu popped up showing that he had a ghost detector and Knifey in the inventory. He selected Knifey, but nothing happened as far as he could see, maybe because he was already holding it. His soul was pulled into the box for a moment before landing back on Fight. Jimmy moved his soul over to the Act button, he had a good idea what Mercy and Fight did.

Another menu popped up showing the options Check and Talk. He chose Check, just to spite Toriel.

A training dummy. Doesn't seem quite right.

The dummy had a turn and Jimmy pressed Fight. Once pressed a menu came up, obviously to select who to attack. He selected the only option, the dummy, and a power meter straight from a video game popped up. He let his turn pass, just to see what would happen.

The dummy floated up through the roof.

The black receded, showing an unreadable expression on Toriel's face.

Jimmy looked up at the ceiling and fiddled with Knifey while Toriel was coming to grips with what just happened.

Then he smirked, having come up with a spur of the moment plan. "Hey Toriel, since… that… just happened, could I try it on you?"

Toriel shook off her shock. "Well I suppose…"

Jimmy cut her off with a screech of "SECRET!" as he pulled Knifey, intent on slicing her in half. Millimeters before it would have connected, he felt the black fight screen activating, cutting him off and throwing him back a couple feet.

"Did you just try to kill me!?" Toriel bleated.

"I'm Jimmy Casket, world's most renowned murder. Of course I just tried to kill you, and everyone else down here shall know my secret!" Surprise has been lost, time to gloat.

Toriel recoiled in shock and horror, before steeling herself. "Very well, I'm sorry."

She raised her hand-paws, releasing a torrent of fire that Jimmy just barely dodged. She's fast, but he's faster and armed with a knife.

It came to Jimmy's turn and he selected Fight, charging forward just as the bar reached full with a full screech of "Do you wanna know my secret!?"

Toriel had no chance to react before Knifey was buried in her chest. Jimmy leaned forward to her ear and whispered, "This is for stealing my kill."

He yanked Knifey up, bisecting Toriel's upper half before her body collapsed into dust, leaving a white upside-down heart that soon shattered.

The black disappeared, leaving a pile of gold coins and a pile of dust. Jimmy stared at the piles for a second, then yelled "Why Is There No Blood?! I Want Blood!"

Jimmy stalked out of the room, intent on slaughtering everything down here, and making it last.

If there was no blood, he would at least get the screams as he chased them down.

He had secrets to tell.

There was no one left. Nothing escaped Jimmy. Not even the monsters scattered in the derelict purple buildings.

After his unsatisfactory killing spree, Jimmy found a well kept home and decided to take a shower. There was no real reason for this, just that the dust was making it really hard to do anything. How can you sneak kill if you're sneezing constantly?

Looking for the bathroom had the accidental consequence of finding the way out. He still took a shower, and after he dried Jimmy left the ruins, searching for others to kill.

He immediately went back inside to grab a coat because it was so cold. The new area was a snow filled forest, but that wasn't going to stop Jimmy from his complete genocide of the underground.

He was lazily walking down a snow covered path, when a stick broke behind him. Jimmy spun around, throwing Knifey at whoever broke the stick.

There was no one there.

Jimmy retrieved Knifey, continuing down the path towards a bridge. He got to the bridge, before he suddenly couldn't move.

A voice spoke up from behind him. "we need to ask you a few questions."

Jimmy felt something hit him hard on the back of the head.

In the moments before consciousness left him, Jimmy thought, "I'm going to get head trauma."

As Jimmy crawled awake, he heard his apparent captors discussing something.

"papyrus, the knife is covered in dust! you are not going to make friends with it."

Apparently him and Knifey. Jimmy laid still, although he was angry at being called 'it'.

"IT COULD BE AN ACCIDENT!"

"look at his LV, it's 6. that's a lot of monsters killed."

Jimmy couldn't help it, he had to brag about his kills. "Of course! Everyone in that purple place is dead. HAHAHAHA!" He gloated as he sat up and looked at his captors.

His two captors were skeletons, one taller and one shorter, and even on bones the disturbed look generated from his insane laughter was visible.

The taller skeleton stuttered, "B-BUT…"

Jimmy grabbed at Knifey and threw it at them. Or would have, if it wasn't missing.

He spent a panicked moment searching for it before realizing that it was gone. Then he was furious.

"Who Took Knifey!" he screeched.

The shorter skeleton looked angrily at him, "why would we let you keep a weapon when you're trying to kill us?"

Jimmy screamed in rage, throwing himself at the skeletons and being barely blocked by the wooden bars between them. He continued to try and kill them for some time before finally sagging against the bars, still giving the skeletons the stink eye.

The shorter skeleton glared at him as the taller skeleton gave him a look of pity.

"WHAT IS YOUR NAME, HUMAN," he asked.

Jimmy gave a glare. "Jimmy Casket."

The smaller one spoke up, "what did you do with the kid? brown hair, this high, striped shirt?"

"Midget with a pink striped sweater I killed a week ago?" Now that Jimmy was thinking about it, the ghost that chased Johnny down here looked awfully familiar. He started laughing again at the irony.

Because Jimmy was laughing, he missed the heartbroken look on the skeletons' faces.

The Q&A continued, Jimmy learning that the shorter skeleton was named Sans and the taller one was his brother Papyrus. Jimmy also realized that the bars were big enough that if he turned sideways, he could slip through, although he didn't use that fact just yet. Eventually the skeleton brothers left and Jimmy slid out.

He easily found Knifey, because it was laying right outside the cage.

They were dumb for leaving it here, and he was ready to show them just how dumb.

At least they didn't take the coat, this black trench coat was keeping him nice and warm in the snow.

The town, Snowdin, didn't know what hit it. Within fifteen minutes, no one was left.

The monsters are stupid to think that everyone gathering in one spot provides protection. It just helped Jimmy, he didn't have to go looking for them. The armored dogs barely lasted thirty seconds, and they were apparently the royal guard.

It just made him angrier, no blood, no chase, and no fight. Everyone was going to die on principal at this point, it wasn't fun.

With everyone dead it was weird that the skeletons were nowhere to be seen. Jimmy just moved on, hoping that they were somewhere up ahead.

They were. Or at least Papyrus was.

"HUMAN, STOP THIS NEEDLESS KILLING."

Jimmy mimed thinking, "Hmmm, no. I prefer to hear the screams."

Sans stepped out from behind his taller brother, "do you really want to have a bad time?"

Jimmy gave a crazed smile and replied, "Do you wanna know my secret?" He charged forward, getting ready to slice the skeletons' spines.

The black showed up and stopped him just like before, but he didn't care, it was killing time.

Both skeletons summoned a plethora of bones, trying to make it so Jimmy would at least be hit. Jimmy didn't care and sliced the attacks in half before charging at the taller brother, forgoing the button. He nicked Papyrus's arm as the skeleton dodged, rendering it useless. Another wave of bones flew at him, he dodged and attacked the brothers again. The brothers dodged and sent another wave of bones.

This dance repeated, over and over again. As this continued, they had a mid-fight conversation. Why they did that Jimmy had no idea, but if they were talking, they weren't concentrating on fighting so it was a win-win for him.

"down here does not work the same as up there. that kid you killed? Would have fallen down here and either saved us all, or killed us."

"So what, you can tell the future?" Jimmy asked. If they could, that would actually be kinda cool, he maybe would allow them to live a few more seconds. Maybe.

"TIMELINES ACTUALLY. AND A TIME LOOP CAUSED BY DETERMINATION."

There was a lull in the fighting, and Jimmy took a moment to process this, before he started to laugh.

"HEHEHEHAHA! I can kill you infinitely!"

The brothers weren't expecting an attack in the middle of the laughter, so when Jimmy suddenly launched Knifey at Sans, he had no time to dodge.

"SANS!" Papyrus cried in anguish as Sans was immediately dusted.

Jimmy took no time to grab Knifey and charge at the remaining skeleton with another screech of his catchphrase, "Do you wanna know my secret!?"

CRACK!

Jimmy was now alone.

"Hehehe… Well, if I wanted to I could kill you indefinitely. However, I prefer my victims to stay dead. Stupid Acachallas..."

Jimmy hated to admit it, but his genocide was getting to be boring. Well, more boring than it already was with no blood.

There was nothing new, no one put up a fight, no one had anything else to add about the time loop thing.

It was getting stale.

The ghost that was down here was new, but died just as easily as the ghosts up above. Having a ghost killing knife would do that.

However, Jimmy was just coming up to the end of the swamp that was after the snow forest, and apparently the head of the royal guard was up ahead. Even though the rest of the guard was pitiful, the leader must give some challenge, right?

There was only a soft whistling noise as warning before Jimmy was quickly forced to dodge out of the way of a falling spear as the black came back. The spear was held by what was obviously the royal guard's leader. The leader of the royal guard didn't have her helm on, showing she was an anthropomorphic fish. It was probably a bad idea to laugh at the person who wants to kill you, but Jimmy did it anyway, "Hahahahah! You're a fish! What, you planning on splashing me to death?"

He had to limbo out of the way of a spear trying to stab his eyes. Jimmy quickly recovered, spinning around, deflecting another spear with Knifey. In another quick movement, he bisected the fish through her armor. He turned around, expecting the black to recede, but it didn't.

The fish was still alive.

He grinned and turned back around to the fish giving him a toothy grin right back.

"I'm not going down that easily, the entirety of the underground is counting on me," the fish stated. The black was momentarily replaced by a blinding light, and when Jimmy could see again, the fish had gotten an upgrade.

Jimmy was unimpressed. "So what, you survived my first attack and got hearts inscribed on your armor? That's it?"

There was no response as he was forced to dodge out of the way of a wave of spears. He shut up and concentrated on fighting.

He killed the fish.

Jimmy was laying on the floor beat up and covered in cuts, but he had killed the fish.

And what a fight it was.

Attacks that should have killed her, she shrugged off. Spears that he should have been able to bat aside, stayed the course and hit him.

And now he was laying there, waiting for his supernatural healing, gained from the ghosts he killed, to fix him up.

From the fact he was still in pain, it would take awhile.

Still, he laughed. He hadn't had anyone that fun in a while.

He still got to tell his secret at the end of the day.

After the fight with the fish, nothing matched his skill.

Even the robot that was specifically designed to kill humans, died in one hit.

The search for the last of the inhabitants was fun, but they all died in one hit.

Flowey, back from the dead apparently, died in one hit.

The king, the strongest of the monsters, died.

In.

One.

Hit.

It was infuriating.

Even the barrier that had kept the monsters underground broke in three hits. Three hits!

Now, there was nothing left, only blackness. Blackness meant that there was a fight.

"Greetings. I am Chara."

A child eerily similar to the child Jimmy killed and chased Johnny into the hole stood before him. The skin was much paler and the cheeks were permanently blushing but that was the extent of the differences.

Jimmy was tired, annoyed, and wasn't in the mood to talk. The kid, Chara, was left to talk with no interruptions.

"Thank you. Your power awakened me from death. My 'human soul'… my 'determination'… they were not mine but yours."

Jimmy was not paying much attention, really just mentally poking at Johnny to see if he was awake yet.

"You. With your guidance. I realized the purpose of my reincarnation. Power. Together, we… Why are you laughing? "

Jimmy may not have actually listened to all of what Chara said, but he heard that last part. Oh how wrong this kid was.

For several minutes all that could be heard was laughing.

"Why are you laughing?!" Chara demanded.

Jimmy laughter trailed off into giggles, then his answer, "You honestly thought I did this for power? They were there! It didn't matter that they were so easy to kill, they died! I'm a killer! It's on principal."

With the answer delivered there was no more sound.

Chara realized the implications.

"You will kill me."

Jimmy gave an insane grin. "Of course," he said, "Now let me ask you a question."

Chara leaned back as Jimmy leaned forward, whispering, "Do you wanna know my secret?"

Suddenly, Chara pulled out a blood red knife and aimed it at Jimmy.

"You are not the only one with a knife," Chara said.

He laughed again, calling out, "Stab Stab Stab!" and the game was on.

Jimmy stabbed, Chara batted it away.

Chara slashed, Jimmy dodged.

Jimmy slashed, Chara ducked.

Both of them had very different fighting styles. Jimmy went for close combat and scare tactics, while Chara played defense until there was an opening. Jimmy always left himself open after an attack, that was how he worked, but that was helping Chara

Jimmy slashed up, Chara dodged.

Chara jumped at Jimmy, Jimmy dodged under her.

Jimmy stabbed, Chara moved out of his reach.

Jimmy was already tired from walking through the entire three mile long underground, searching out and killing all its inhabitants. If something didn't happen soon to tip the fight in his favor, he would lose this.

Chara tripped him.

Jimmy landed hard on the ground.

Chara stepped on his chest.

"Pitiful," was all that was said.

Jimmy, thinking fast, remembered that he had something else in his inventory. His soul moved to the buttons, unused since his fight with Toriel, and selected Item.

He pulled out the ghost detector and threw it in Chara's face causing the child to fall off of him.

Jimmy seized his chance. Leaping up to a standing position, he grabbed Chara in an one armed bear hug as his other arm forced Knifey into her spine.

"Do you wanna know my secret?" Jimmy repeated as leaned into her ear, digging Knifey farther into her back.

In a whisper he said, "I actually liked you."

Jimmy threw Chara into the air, ripping his knife out. Right before the body hit the ground he sliced up, cutting longways from legs to head. The two halves flopped onto the ground on either side of him, coating him the blood he desired.

He laughed and laughed as the black dissipated for the last time. He shed the coat he had been wearing, regretfully removing most of the blood and not so regretfully removing most of the dust. In a rare moment of respect, he laid the coat on the halves of Chara and trudged up out of the cave.

He made it into the sun, before tripping and landing on the ground.

He turned over and looked up at the orange sky, his vision fuzzy. He felt his eyes shifting back to Johnny's blue as he slowly lost control, as Johnny regained control.

Jimmy honestly didn't care, he needed a nap anyway.

Once back in control, Johnny made his way down the mountain, none the wiser as to what had transpired. With the only witness of the crime the murderer, no one ever truly found out what had happened under the mountain, the underground a casket for the forgotten monsters.