Scooby-Doo Meets the Undertale Monstersion

Mystery Solved and Epilogue

"And we are back, ladies and gentlemen!" Mettaton announced loudly, "The time has come to unmask the maddening mystery beneath this dark armor! But first, let us see if our mystery solvers have already deduced the culprit's identity!"

MK had recovered from Frisk's kiss, and had gotten off of Scooby and was standing confidently as he said, "Oh, it's obvious who the ghost is. It's Susie. She doesn't want Monsters and humans to be friends, so she sabotaged Mystery Inc.'s visit by stealing Undyne's armor and scaring everyone. And those flaming spears she threw at us were really those fireworks we saw her sneaking around with."

Fred shook his head and said, "No way. I don't think an average school bully would be smart enough to pull this off. If you ask me, the prime suspect in this mystery is Undyne herself."

MK and the Dreemur kids stared at Fred is shock.

Frisk shook her head and said, "No way, Fred. Undyne can't be the culprit. I mean, she's the one who had her house broken into."

Fred replied pointedly, "Hey, that fish Monster has been a jerk to us the whole time. I wouldn't put it past her to have faked the entire thing just so she could scare us out of town."

Chara gave Fred a flat look and said, "Fred. You're an idiot."

Asriel winched at his dead sister's words and said, "Gosh, Chara. Kinda harsh."

Fred shrugged and said with a smile, "I'm just saying, we never saw Undyne and the Haunted Armor at the same time."

"Did someone say my name?!"

Everyone turned to see Undyne herself walking into the alleyway. She smiled a toothy smile and said, "Heh. Look at that. You caught the so called ghost. With ice, huh? Fufufufu. . . way to go Kid."

MK smiled at the compliment, while Fred looked utterly embarrassed as he backed up and muttered, "Oh. . .well, nevermind. Sorry."

Frisk nodded to Undyne and asked, "You have any idea who the culprit is, Undyne?"

Undyne's smile collapsed into a frown, and she remarked, "You dorks really want to know what I think?" Without waiting for an answer, Undyne whirled around and glared at the Haunted Armor, saying, "I say, it's Papyrus! The way he dived through my window was a dead giveaway!"

"WHAAAAAAT!" MK shouted in disbelief, "YO! No way! Papyrus would never do something that bad!"

Undyne folded her arms, not turning around to look at Monster Kid as she said bitterly, "Oh yeah, well why shouldn't he finish what he started? You already found a new hero in him. What better way to get me out of your head completely than to have my armor running around causing chaos and scaring you. It's the perfect plan!"

"Huh?" MK said, confusion evident in his face.

Undyne closed her eye and sighed. "Fine. I guess I blew it, so I might as well come out and say it. I got jealous when you stopped looking up to me and started admiring Papyrus. You used to be all about being strong and tough and brave like me. Sure, it got on my nerves at first, but I kinda liked it at the same time. But now you're all about solving puzzles and being nice and smart and stuff. It just sucks that you don't think I'm cool anymore, and the fact that Papyrus is my best friends just makes it worse-."

"But I DO think you're cool!" MK shouted pleadingly.

Undyne's eye blinked open, then rolled as she remarked, "Come on, Kid. I overheard you talking about how mean I am."

MK looked down in shame and said, "Yo. . .yeah, I did say that. But I figured that's just cause you're tough, and sometimes you gotta be mean to show people who's boss, so they'll listen to you and stop doing whatever bad stuff you caught them doing. Yo, like that." MK then looked up at Undyne's back and said in earnest, "Yo, just cause I wanna be more like Papyrus doesn't mean I don't still think you're cool too. I always thought that it was awesome that you and Papyrus were best friends. Yo, you were the perfect team. You're super strong and powerful, and Papyrus is tough too but he's also clever enough to solve any puzzle that gets in your way. You'd be like a superhero, and Papyrus would be your super cool sidekick and stuff, yo!"

MK then carefully walked around Undyne in a rather timid manner, and then looked up at her and said, "Yo. . . so, I still think you're a true hero, cause you fight for what's right and stuff. And Papyrus is a cool hero too that's always ready to help when you need him. Yo, just cause I think I'd be better at helping people like that, and could probably never be like you, doesn't mean I don't think you're a cool hero and stuff."

Undyne stared down at MK, her face unreadable as her eye studied the child's face. Then, Undyne finally cracked a genuine smile and said, "Well, you're a sweet kid to say all that. But don't sell yourself short. You could totally be as brave and strong as I am. I mean, heck! Look at what you did to that ghost! You're gonna go far kid. Just keep your confidence up and you could be as cool as both of us combined someday."

MK's eyes widened at the thought. "Yoooooooooo. . ."

Undyne then turned the rest of the group and held her hands up. "Alright, I take it back. Papyrus is not the culprit. He's way too nice, so there's no way it's him. I was just pissed and accused him without thinking."

Daphne put a hand on her hip and said, "Well, what about Burgerpants?"

"WHAT!?" Mettaton exclaimed, "One of my own employees? Scandalous!"

Daphne eyes Mettaton suspiciously and said, "Especially if you were the one who ordered him to do it?"

"PREPOSTEROUS!" Mettaton shouted back, sounding genuinely insulted.

Frisk nodded and said, "I think Daphne might be onto something."

Daphne pointed at Mettaton and said, "You've been exploiting this mystery to promote your brand the whole time. And there's also that clue that Frisk found earlier."

Frisk held up the welding gloves Burgerpants had dropped and said, "That's right. Burgerpants could've worn these gloves while using welding equipment to melt Undyne's lock, making it look like a Monster used fire magic to do it."

Mettaton snatched the welding gloves out of Frisk's hands and said, "I gave Burgerpants these gloves to weld some leaky pipes in the restaurant! I would never fake something like this for my own gain! Who do you think I am, Dr. Alphys?"

"Who's Dr. Alphys?" Daphne asked.

"Long story," Frisk muttered.

Chara flew up above the group and said loudly, "Hold it, hold it everyone! You're all making this harder than it is. We need to focus on the clues that matter."

Velma stepped forward and said, "Chara is right. The way I figure, we have four main pieces of evidence that point directly to our culprit: the date when Undyne's house was broken into, the melted lock, the brown powder, and the way the Haunted Armor acted whenever it went after Frisk, Asriel, and Monster Kid."

Chara floated next to the frozen armor and said pointedly, "Exactly, and those clues could only point to one person."

Velma stepped over to the armor and grabbed onto the helmet as she said, "Isn't that right, your Ex-Majesty!"

Velma then removed the Haunted Armor's helmet to reveal the culprit's true identity.

"TORIEL DREEMURR!?"

"MOM!?" Frisk and Asriel exclaimed in wide eyed shock.

"Answer your phone, Azzy, cause I totally called it!" Chara said with her arms folded and a smug look on her face.

Toriel pouted and said, "How did you know it was me?"

Velma explained, "The armor was stolen three days ago, right after we confirmed that we'd visit via Email. At that point, three parties knew about it: Toriel, Asgore, and the staff at the Visitor's Center. Asgore is way too big to fit in the armor, and it didn't seem likely that someone at the Visitor's Center would go through all that trouble, making Toriel the prime suspect. But there was still the chance that word might have leaked out and that it was someone else entirely. But then the melted lock narrowed it down to someone with fire powers, and the job was done so neatly that it couldn't have been done with a propane torch or welding tools. It had to have been magic."

Shaggy nodded and said, "And, like, it also explain why the armor didn't chase us into the school. Toriel is a teacher there and didn't have the heart to chase us through it and wreck the place."

Chara then added, "And it also explains why the armor went wild when it went after Mystery Inc., but held back whenever it chased us. Of course Toriel would never want to hurt Frisk or Asriel, or MK."

Velma smiled and took out the zip-top bag of the powdery substance she'd taken a sample of. "But the biggest clue was the brown powder we found where Undyne's armor used to be," Velma said.

Undyne frowned and said, "How exactly is dirt or sand or powder or whatever the biggest clue?"

"It's not dirt or sand or powder. It's cinnamon," Velma revealed.

Daphne's face lit up in realization, and she said, "Of course. Toriel mentioned she'd spilled a bottle of cinnamon because she was nervous about us coming. Some of it must have clung to her fur, and come off when she put on the armor in Undyne's house."

"But WHYYYYY!?" Asriel shouted with tears in his eyes, "Why did ya do it, Mom? I don't understand!"

It was Velma who answered the boy's question, "Because she was worried that Mystery Inc.'s habit of catching Monsters would make it harder for Monsters to integrate into human society. She figured that if she made us look bad, incompetent, or dangerous; then we would decide to shut-down for everyone's own good."

Toriel hung her head in shame and said, "It's true, my children. If Monster kind is to have any kind of future, we'd need to expand far beyond the relatively small area around Mount Ebott and go out into the world. But if we have to worry about being caught up in some sort of mystery and captured by either Mystery Inc. or a group emulating them, then how could we possibly pursue our hopes and dreams? I had to do something to put an end to Mystery Inc., so I came up with the idea of creating a mystery that they wouldn't be able to solve so they'd retire. When I grabbed Monster Kid, I planned to let him slip away so that he'd beg them to stop their investigation. But then it backfired. You were all so Determined to keep meddling. Even when I chased after you directly, and even used my advanced fire magic skills to create spears of flame, you still wouldn't give up. At that point I didn't know what do, and thought if I started scaring everyone in town, they might convince them to quit. . .but. . .but I was fool. All I did was cause so much chaos. . .I'm so ashamed. . .and sorry."

Asriel made a face as he thought through the explanation, while Frisk took a moment to gather her thoughts and then said, "But, Mom. Mystery Inc. aren't just a bunch of Monster hunters. They solve crimes and catch criminals. Sure, they went after Monsters, but real Monsters didn't exist on the surface before. But now that they do, they'll be sure to give them a fair chance."

"Yo, and Mystery Inc. is really nice and cool and smart and stuff!" MK said as he nodded his head excitedly, "All they want to do is help, and they did. They've been really friendly to us Monsters. They aren't a problem at all!"

Toriel sighed and said, "I believe you're right, and perhaps I had begun to see it earlier, but I just couldn't bring myself to accept it. I made a horrible decision, and a terrible mistake. I am so truly sorry, and I deserve whatever punishment I receive."

Mystery Inc. all felt quite a bit of sympathy for the Boss Monster. They exchanged glances, and then Fred said, "Well, nobody got hurt, so maybe-."

"Ahem!"

Everyone looked at Undyne, who stood with a slight scowl on her face. When she was satisfied that she'd gotten everyone's attention, she said, "How about this: If she pays for Nice Cream Guy's cart, Catty and Bratty's cart, and my window; and apologizes to everyone; and polished my armor. . .then I think we'll all be square. You okay with that, ma'am?"

From her icy prison, Toriel nodded and said, "Of course. Whatever you say, and I am truly sorry for what I had done to you, Undyne. I had betrayed your trust-."

"Yeah, yeah, whatever," Undyne said quickly, and she summoned a spear and sued the butt of it to shatter the ice around Toriel.

The Boss Monster gasped as she fell down to her knees. As she slowly got up, she remarked, "Well, one thing I must admit. I would have gotten away with if it weren't for my meddling children. . . and their friend Monster Kid."

Late the next day, much of the town had gathered together to see off Mystery Inc.

"Now, don't be a stranger, Shaggy Rogers! You are my best customer!" Mettaton said.

"PERSONALLY, I WOULD LIKE TO LEARN THIS VENTRILIQUISM SKILL SHAGGY IS A MASTER OF!" Papyrus chimed in.

"Like, I totally loved those tips Daphne gave us for our business," Catty said.

"Like, yeah! Who knew that you could make all sorts of cool stuff like lock picks and power cells out of stuff people throw away!" Bratty said, still sounding quite amazed.

"i think you should have a better sense of humor after hanging around me for a while, Freddy," Sans said with a nod.

"I s-sure appreciated your help and company V-Velma. It's r-really nice to have another highly intellectual p-person other than Chara to t-talk to," Dr. Alphys said with a nervous smile.

"Your visit has most certainly been a blessing, Mystery Inc.," Asgore declared with a broad grin.

Firsk, Asriel, Chara, and Monster Kid were all gathered together in front of the group, smiling widely at the four humans standing next to the Mystery Machine.

"We all hope you come back and visit someday," Chara said.

"Like, no problem, guys. You're all the grooviest!" Shaggy said as he pointed at the four of them.

Fred stood proudly and said, "And we'll be sure to spread the word about how great Monsters really are."

Undyne flashed a wicked smile and said, "Sure ya will. But if you find any Monster criminals, whether it be human imposters or real Monster crooks, don't be afraid to give 'em a thrashing for me!"

"Yo, wait!" MK suddenly exclaimed, "Where's Scooby?"

Velma looked around and said, "Jinkies, you're right. Where could he be?"

Meanwhile, some distance away, hidden behind some bushes beneath a tree, was Susie. She was crouched down low, and she had a large amount of fireworks aimed right at the Mystery Machine.

"Ha-ha-ha. . . this will fix 'em good!" she said with a cruel grin, and she lit a match and carefully brought it close to the large fuse which split apart to go into each of the many rockets. However, a massive splash of ice cold water thoroughly soaked the monster and all of her fireworks.

Susie gasped in shock, and then she heard a mixture of laughing and barking coming from above her. She looked up and saw that up in the tree was Scooby and Annoying Dog, each holding a bucket as they laughed at her. Susie snarled and took off running in a seemingly random direction, yelling furiously, "I'll remember this!"

Scooby and Annoying Dog smiled at each and gave each other a triumphant high-paw.

Firsk, Chara, and the Monsters of the town all called out their goodbyes as Mystery Machine revved up and drove out into the sunset. And as the van drove out of sight, Scooby stuck his head out of the window and called out, "Scooby Dooby Doooooooooo!"

2 Weeks Later. . . .

"Aw, come on! I wasn't even close!" MK shouted.

Chara, Asriel, Frisk, and MK were all lying outside on their stomachs on the grass in their yard. All four of them were focused on an open mystery novel open to the last chapter.

Chara was smiling smugly once again as she floated up into the air and pumped her right fist in victory. "Heh. Admit it. When it comes to solving mysteries, none of you can compare!"

Asriel pouted and said, "Just wait, Chara. I'll solve the next one!"

Frisk suddenly raised her head and looked out at the sidewalk. "Look, it's Dr. Alphys. She doesn't look good."

Everyone turned to see the scientist huffing and puffing as she stiffly speed-walked down the street.

Asriel got up and called out, "Dr. Alphys? Is something wrong?"

Dr. Alphys stopped for a moment and turned to look at the children as they all got up and approached her. Sweat beaded down her head as she said, "Oh, d-don't worry. It's n-nothing you kids have to worry about. It's m-my fault for going back to the True Lab."

Frisk was curious. "Why were you down there?" she asked.

"I l-left some notes and d-documents and d-data down there," she said, then she shivered and said, "Who would've thought it was going to be haunted by the previous Royal Scientist!"

"Haunted?!" the four children echoed.

Dr. Alphys appeared even more panicky, and she stammered out quickly, "Oh d-d-dear, I said to much. Forget I said anything! I gotta talk to Undyne! Bye!"

The kids watched Dr. Alphys run off, and when she was finally out of sigh, and earshot, Chara smiled mischievously, turned to the others, and said, "Are you thinking what I'm thinking?"

Frisk and Monster Kid gained smiled identical to Chara, and then they both turned to look at a confused looking Asriel. The young Boss Monster looked back at his sisters and friend, and with a very nervous look on his face, he said only one thing.

"Uh-oh. . ."

A human girl, two monsters, and a ghost girl rode the elevator down into the True Lab.

Asriel and Frisk,

Chara and Kid,

We got some work to do now

Asriel gulped nervously, and the group made their way through the corridors of the lab.

Asriel and Frisk,

Chara and Kid,

We need some from help from you now

After they walked by a Potato Crisp vending machine, the machine slid away to reveal a secret passage, and the form of W.D. Gaster stuck its head out.

Chara pointed down a hallway and the group proceeded, oblivious of the limb that grabbed at Chara's hair.

Come on Asriel,

I can tell,

You really don't wanna be here

Frisk leaned against a wall, and a panel slid open causing her to fall backwards into it.

"AHH!" Asriel shouted as a huge grey face spouted out of the floor right behind Frisk and laughed manically.

"RUN!" Frisk shouted as she jumped up and joined the group in fleeing.

But you are not alone,

So don't run home,

Don't give in to your fear

A grey, dead eyed humanoid Monster appeared in front of them, and Asriel briefly clung to Frisk and MK in fear before the group turned and fled again.

MK suddenly stepped onto a pipe lying on the floor and rolled out of control, crashing right into a safety show which doused him with water.

In spite of everything, Asriel couldn't help but chuckle at this.

You know we got a mystery to solve,

And we know that Firsk is gonna ACT

Chara gasped and pointed again, and everyone turned to see a tall, thin, grey monster that was holding his own living face in his left hand.

Don't hold back!

Asriel hugged Frisk again and shut his eyes tightly, while MK jumped up and ran off screaming. However, MK was cut off by a ghostly, greyed out version of Clam Girl. MK dived into a nearby empty storage drum. His feet popped out the bottom and he ran blindly down the hall, turning a sharp corner.

And keep in mind, if you come through

You'll get some butterscotch pie, in fact

How 'bout that?!

Still in the drum, MK ran into something. He popped his head out, and was face to face with W.D. Gaster.

The rest of the group peeked around the corner, and Asriel cried out in fear, his ears sticking up comically. Chara desperately tried to shush him in vain.

Asriel and Frisk,

Chara and Kid,

You're ready and you're willing

As Gaster raised it's hands and leaned towards MK, it's eyes glaring right down at him, the young Monster jumped out of the drum and ran right past Asriel and Frisk, causing them to spin around, and right through Chara.

The three of them were disoriented from this, but quickly recovered and turned to look down the hall.

Asriel and Frisk,

Chara and Kid,

I know you'll catch that villain!

The three of them screamed when Goner Kid ran at them out of the darkness. But then the figure shook the soot and dirt from the drum off of himself, and chuckled as he revealed himself to just be Monster Kid, much to the Dreemurr kids' annoyance.

The End

Well, that was fun to write. Although I'm slightly worried that I didn't write the mystery good enough. I felt I left a good amount of clues, while also providing an okay amount of red herrings. I hope you all enjoyed this story, because more Undertale content from me is coming. I plan to write a story about how I believe Asriel can be saved and Chara could come back as a ghost. Keep an eyes out for that. Also, do you feel this mystery was fair? Were you able to figure out that it was Toriel? And do you want to see the Undertale Children solve more mysteries? Because believe it or not, I have at least two more ideas: "The Terrifying Teaching Skeleton" "Night of the Were-Flower".

One more thing: I put plenty of Scooby Doo and Undertale references in this story. The scene at the karate school was inspired by a comic in the Growthspurt AU. I won't point out the Scooby Doo references though. Find them yourself! It's fun!

Thanks for reading, and goodnight!