"So here's what we got!" Adagio said as she laid a map of Canterlot Town on the table, with two areas circled in red. "According to my research, these two are the most likely to be Nightmare Moon's next target." she pointed at the red circle on the top right of the map. "The 22nd Corner Art Gallery will exhibit the latest works of the renowned artist Brush Stroke tomorrow, and some art fanatics are willing to pay a couple tens of grands for any never before seen project of his." she then pointed at the red circle close to the center of the map. "And the L. Faust Museum Of History has been advertising their new Renaissance Wing for a while now, but crates were only delivered there today."

"Isn't it obvious that Nightmare Moon is going after the goods in the museum?" Aria asked with her arms crossed.

"We're dealing with a greenhorn here. A very skilled one, but a greenhorn nonetheless. No one knows her modus operandi yet, so we must cover all the possibilities! And that's why I want you to split in two groups; Trixie and Aria, I want you two to guard the art gallery while Sonata and Sunset guard the museum."

"Got it! Make sure to keep an eye on those cameras, she might get careless. " Sunset Shimmer ordered. "And watch out for anything suspicious, too. We can't cut the criminals some slack just because we're working on a bigger case!"

"Waaay ahead of you!" Adagio said with a smirk as she pointed with her thumb at the computer with three screens behind her, each screen showing a different part of Canterlot Town. "Now go out there and catch that bandit."

"But remember what I said; don't be too rough on her and don't call the police. We need her!" Sunset warned.

"Yes, we get it." Aria said as she wore her Maiden mask. "Are you ready to go, Trixie?"

"Since before Adagio explained the plan!" Trixie said as she jumped out of the window, soon followed by Aria.

Sonata was lying down on the roof of the cafeteria across the street from the museum, wearing her night vision goggles.

"Bring it on, Nightmare Moon! I am ready for you this time!" she muttered to herself as she tapped the earmuffs she was wearing. While most people wouldn't hear a single noise while wearing those earmuffs, Sonata could still hear like a normal human thanks to her hyper hearing.

"How are things on your side, Bacon Strips?" she asked.

"Everything is quiet around here, Taco Master." Sunset's voice replied through the communicator. "And are you sure we need codenames? I'm pretty sure this frequency is safe."

"You can never be too careful, Bacon Strips. What about you, Pinecone and Vocaloid?"

"Stop calling me that!" both Aria and Trixie said at the same time.

"I'll take that as 'all good'!"

Two facts allowed Nightmare Moon to sneak up on Sonata: the first was the fact that she had earmuffs on - but her hearing was too sharp to be blocked by them, so she could still hear perfectly fine, just not as good as when without them. But what got her was the second fact: she allowed herself to be distracted by the conversation with her teammates. Not wanting to waste the opportunity, the thief knocked the girl out with a blow to the back of the head.

"What was that?" Sunset asked. "I heard something!"

"Wasn't me!" Trixie said.

"It wasn't here either." Aria said. "Sonata?" no answer. Aria groaned. "Taco Master, you there?" still no answer.

"It's not like Sonata to just shut up like that." Sunset said. "I'll go check on her!"

Aria and Trixie waited for news about their partner's situation, but none came. Aria groaned again.

"That's it, I'm going there!"

"We're supposed to guard the gallery!" Trixie warned.

"If Sonata and Sunset aren't responding, it's more than obvious that Nightmare Moon got them. Which means that her target is the museum, not this stinking gallery!"

"I guess you have a point."

Aria and Trixie ran straight to the museum, where they located the unconscious Sonata.

"Make sure she's ok, then go look for Sunset." Aria ordered. "I'm going in!"

Aria Blaze was about to kick the entrance door down, but noticed that all the windows and doors were intact and the power was still on.

"That's strange!" she said as she rubbed her chin. "It's like she never went inside."

"Aria, go back to the gallery, quick!" Adagio ordered through the communicator.

"Something wrong?"

"Nightmare Moon is there!"

"What?!" without thinking twice, Aria ran back to the art gallery as fast as her feet could carry her, arriving just in time to see the girl called Nightmare Moon exiting the building through the front door with several paintings strapped to her back. "How did she...?!"

When she noticed Aria standing on the other side of the street, Nightmare Moon unstrapped the paitings from her back and assumed a fighting stance.

Aria chuckled. "And just like her predecessor, this kid has guts." she then cracked her knuckles. "Guts that I'll spill all over the street if you don't surrender, you hear me?" Nightmare Moon could hear her, but she wasn't listening to her and kept her fighting stance. Aria shrugged. "It's your funeral!"

Aria jumped and tried to spin kick her in midair, but Nightmare Moon ducked. Her eyes widened when Aria's kick broke one of the thick marble columns next to the gallery entrance in half, but she wasn't about to kneel and beg for mercy. Aria's next move was a barrage of punches, but Nightmare Moon managed to dodge each punch individually. Angered by the fact that she was being taunted, the Maiden armed herself with the closest thing she could find: a "Stop" sign on a metal pole.

Still impressed by her foe's superhuman physical strength, Nightmare Moon just kept dodging, knowing full well that close combat would be her demise. She had to think of a plan to--

The sound of police sirens approaching distracted her; not enough for Aria to hit her, but enough for the edge of the "Stop" sign to tear her mask a little and make a small cut on her cheek. Trying to cover her face, she circled the Maiden and grabbed the paintings tied together next to the gallery entrance.

"Oh, no, you won't!" Aria jumped on Nightmare Moon and tried to immobilize her, but the burglar was more flexible than she looked, easily slipping out of the vigilante's grasp. Aria kept trying, though, and managed to slip her fingers in the tear on her mask. Nightmare Moon tried to escape, but her only accomplishment was making the hole bigger, revealing her face to the Maiden; her light amber skin, her moderate cyan eyes and strands of her gold and crimson hair. Shocked by the revelation, Aria dropped the pole and just stood there as Nightmare Moon fled with her loot, the Maiden's cape being the only part of her that moved.

"Look! Over there! It's the Mysterious Maiden Do Well!" one of the police officers that just arrived at the scene said to his driving partner.

One of the policemen approached her. "Um, excuse me, miss, but I'm going to need you to--" he placed his hand on her shoulder, bringing her back to the real world. Before he could finish his sentence, Aria jumped on a wall and scaled it, leaving behind several holes that she created with her brute force for leverage.

"Hey, I'm here!" Sunset Shimmer said as she entered her apartment, closed the door and took off her mask. "Sorry for taking this long and not calling you, but my communicator was--" she looked around and saw her friends looking at her - Aria looked angry, Trixie looked hurt and Adagio and Sonata looked sad. "What?" in the blink of an eye, Aria tied a rope around Sunset's wrists and then around her ankles. "Hey, what the-- Whoa!" she lost her balance and fell hard on the floor. Aria, Trixie and Sonata surrounded her, but Adagio just looked back at the computer screen.

"So that's what this was all about, huh?" Aria said. "'Don't hurt her', or 'don't call the police', you were just playing us!"

"How could you lie to us, Sunset?" Trixie asked with clenched fists. "How could you lie to me?!"

"Wh-What are you girls talking about?"

"I'm sick and tired of you playing dumb, Sunset Shimmer! Just admit it: you are Nightmare Moon!"

Sunset Shimmer raised an eyebrow. "I know you have zero sense of humor, Aria, but you need to try to tell a joke this bad!"

"A... A JOKE?!"Aria was so furious that the veins on her forehead looked like they were about to burst. She grabbed the suspect by the chin and practically pressed her face against one of the computer screens, which showed a screenshot of footage of Sunset Shimmer wearing the Nightmare Moon outfit with a torn mask and carrying on her back the stolen Brush Stroke paintings. "So this looks like a fucking joke to you? It doesn't look like one to me!"

Sunset's eyes widened. "N-No no no no no, t-there must be some kind of mistake! That's not me. That can't be me!"

"You and Sonata were patrolling the same area. Suddenly, Sonata is knocked unconscious and you disappear for the rest of the night! Then Nightmare Moon shows up in the place Trixie and I were patrolling as soon as we leave, as if she knew exactly what we had planned from the beginning. Then I manage to remove her mask and guess who was under it? Here's a clue:" she banged her fist on the table, nearly breaking it in half. "It wasn't Mr. Wickles!"

"Bu-But I didn't steal anything! I found Sonata unconscious and tried to help her, but I was attacked from behind and someone used chloroform to knock me out! When I regained consciousness, I was in a dumpster and my communicator was busted. Whoever this person is, they're trying to frame me!"

Sonata approached her face to Sunset and sniffed her. "Yep! Smells like a dumpster, alright."

"That proves nothing! If you are as innocent as you claim to be, then show us some evidence!" Aria demanded. "Right here, right now!"

"I... I..." Sunset looked at the screen and a little detail caught her eye. "Her cheek! Look at her cheek!"

The four girls looked at the cheek of the girl on the screen, and like Sunset Shimmer pointed out, there was a difference that could have been easily missed: there was a cut on Other Sunset's cheek, while the Sunset they had in the room had no injuries on her face.

"You probably used makeup to cover--" Aria used her thumb to try and clean the makeup covering the cut on her cheek, but there was no makeup hiding an nonexistent wound. "It's not makeup... I-I don't understand, no one can heal and injury that fast and--" Aria covered her mouth with a hand and gasped.

"See? There's your evidence! Can you let me go now?"

Aria let go of Sunset Shimmer's chin and took a few steps back. Trixie immediately untied the ropes.

"I-I-I'm so sorry I doubted you, Sunset. That picture, combined with what Aria said, I... I was so afraid you had betrayed us that I couldn't think straight."

Adagio pulled Sunset into a hug. "I knew you would never betray us, Sunset Shimmer!"

"B-But I'm still keeping my eye on you." Aria said as she crossed her arms and looked, blushing in embarrassment. "D-Don't think you're off the hook yet."

"Don't mind her, Sunny, she just hates to be proven wrong!" Sonata said after joining the hug.

"That's one problem solved, but another problem surfaces." Trixie pointed out. "Who is that other Sunset Shimmer?"

"Oh! Oh! Oh! Can we call her Tesnus Remmihs?" Sonata suggested.

"It looks like we just found out who Tantabus actually is." Sunset said.

Author's Notes:

The Mysterious Maiden Do Well franchise's main objective is to come up with alternate version of the Equestrian people. Sombra, Twilight, Zecora, Chrysalis, Tirek, Discord, Screwball, and now Tantabus! Or is it Sunset Shimmer?
DUN DUN DUNNNNNNN!