Twilight had barely touched down in front of the Carousel Boutique before she blew the door off its hinges with a violent pulse of magic. She ran through the opening into the dimly lit interior of her friend’s shop. Her eyes wide with panic, Twilight began shouting Rarity’s name as she dashed about the racks of clothing, searching desperately.

It had occurred to her that Trixie may still be hiding somewhere within the shop waiting to pounce, but Twilight couldn’t bring herself to take any extra care. She had to find Rarity. Frustration and fear growing within her, she used a powerful blast of magic to knock over the colourful clothes-filled racks and worn looking white mannequins which cluttered the shop floor. The terror she felt for her friend grew into a manic desperation as her scan of the area yielded nothing. Twilight leapt toward the doorway leading to her friend’s inspiration room, wrenching the door with her magic so hard it buried itself into the wall as it crashed open.

As Twilight ran through the doorway into the pitch darkness of the room, something caught under her legs and she fell heavily to the floor, smashing her head on the jam on her way down. Vision blurred from the impact, Twilight shook her head furiously as she tried to identify what had tripped her. Twilight focused magic through her horn casting a dim illumination spell from its tip. The world came into focus and she saw one of Rarity’s white mannequins laying on the floor beside her. Confused she pushed it away and stood, looking about the dark room and once again calling her friend's name. The room was empty save for the silhouette of a few more racks of clothes and another row of mannequins standing by the far wall.

Twilight tried to slow her panicked mind and think clearly. Everything in the shop had been undisturbed when she had entered, and there was no sign of any struggle. Twilight considered the possibility that Rarity was simply away from home, but dismissed it immediately as it was much too early. Twilight started to walk back to the shop’s main room, but stopped in her tracks as a realization hit her. There was one thing out of place. The mannequin she had tripped over should have been lined up with the others. Looking down at it, she saw that she had not knocked it down when she fell, rather, the white construct had tripped up her legs because it was already laying on the ground. The brass rod which served as its stand had been torn away.

The fragile hold Twilight had managed to place on her emotions ripped apart once again as dread seized her heart. She whipped her head up, taking a step forward and looking again through the shadows at the row of mannequins against the far wall. One was different. Twilight took another step closer. The farthest one had a mark on its flank. A Cutie Mark.

“NOOO!” Twilight screamed as the magical illumination from her horn intensified with her rage.

Rarity stood at the back of the room, blood pouring down from her midsection where she had been impaled with the brass stand, her face as expressionless as the mannequins beside her.

Twilight’s mind nearly shattered for the weight of her despair. She whipped her head back and forth from the grotesque diorama as she desperately tried to make sense of the world around her, screaming hard as she wept for her lost friend. But through all her crippling pain and behind the grief, the logical portion of the lifelong student’s mind recognized the puzzle before her. The screams and sobs died down, replaced by a feverish monologue as she attempted to understand what had happened.

“This doesn't make any sense! Why? Why would Trixie escape only to risk it all by coming back to town? And why target Rarity? Think Twilight, think think think!” Twilight said, stamping a hoof as she spoke.

“Okay Okay. Why Rarity? Why not just escape? … She knows escape would do her no good. She knows I would hunt her down no matter where she went. So why not go after me? She must know she can't win that fight. So why Rarity, what makes her different?”

Suddenly she looked up, eyes wide as a thought came. “Of course, the fire gem! The fire gem is the only real proof we have that she committed the murders. She must have recognized Rarity’s magic on the stone! She must think that if we can't craft another stone, we would have no evidence against her! Her next step is to steal the ruby!”

Twilight’s excitement threatened to overwhelm her. She was finally one step ahead of this filthy murderer. She turned and bolted. As she reached the door, she suddenly froze up and skidded to a halt as another thought came to her.

“If she could sense Rarity’s magic in the stone, then that could mean she also may have … Spike!” The world blurred past as she flew faster than she had ever had before.

The sun had yet to peak above the horizon as Twilight arrived back at the library. Panting heavily from her frantic flight, Twilight ignored her fatigue and ran to the doorway, hurriedly opening the portal and rushing inside. The warm glow of the lantern on the table was the only thing greeting her arrival. Twilight began to feel her panic rising up once more when she realized she could hear the soft rolling sounds of a baby dragon snoring. A palpable relief flooded through Twilight’s body at the sound. Creeping silently up the stairway, she confirmed that Spike was still sound asleep in his bed. Twilight felt a great weight lift off her shoulders at the sight of his tiny form. She watched him sleep for a moment before remembering the very real danger they were in. Making her way back downstairs, she moved to the chest sitting on the wooden table and opened the lid. Another sigh of relief escaped her lips as Twilight saw the fire ruby still nestled on its silken cushion. Trixie may still intend on getting her hooves on it, but it truly seemed like Twilight was finally one step ahead of her old nemesis. By now there was no doubt the Captain had informed the other guards and the remaining Elements of the criminal’s escape. Twilight expected they would arrive any moment, and then together they could search out and recapture the murderer.

Twilight began to feel woozy as the adrenaline from the race home left her system. She crossed the floor to the washroom. The purple mare who gazed back at her from the mirror looked haggard and tired. Shaking her head she bent down to splash some cold water from the basin into her face, she sighed as much of the weariness washed away along with the cool liquid.

Looking once more into the dark sunken eyes of her reflection, Twilight felt anger growing in her. Everything she had been through. Everything her friends had been through. All that her town had suffered. She would make sure that Trixie got what's coming to her. She would make sure she suffered. “You’re never going to escape me,” she whispered a vow.

“Haha, somehow I doubt that Princess.”

Twilight's tired eyes shot wide as adrenaline once again flooded her system. She whipped around, seeing Trixie leaning casually against the door frame.

“You!” Twilight raged as her eyes flashed white. She attempted to lash out with a pulse of deadly energy, but to her immense surprise, the magic refused to focus in her horn.

“Tsk tsk tsk, now we can't have you wrecking the place, Princess. That just won't do.”

Twilight's shock at the failure of her magic was complete. “How … How did you do that? You can’t do that. There’s no way you're powerful enough to counter alicorn magic!” Twilight’s stunned question only garnered more laughter from the gloating blue mare.

Trying once again to bring her considerable magical power to a focus, she was rewarded only with a small shower of sparks erupting from the tip of her horn.

“That's impossible!” Twilight growled with frustration.

“That's impossible!” Trixie mocked her rival, once again assuming her voice.

“No more games Trixie!”

“Oh, I’m not playing any games Twilight. And why do you keep calling me Trixie?” The other unicorn accompanied her confusing question with a bright flash from her horn.

Temporarily blinded, Twilight prepared for an attack. None came. Instead, Twilight stared dumbfounded at the mare ahead of her. Instead of Trixie standing in the doorway, what she saw was a perfect copy of herself.

Shaking her head, Twilight roared at her doppelganger, “Drop the illusion, Trixie. It's over!”

“Oh, this is no illusion Twilight. And this is far from over.”

“What are you talking about?” Uncertainty began to edge into Twilight’s voice.

“I can’t stop now. I can never stop. We can never stop,” the other-Twilight said, a disconcerting smile on her lips.

“We’ll see about that!” Twilight said, eyes narrowed in determination.

“Hah, you poor fool. Don't you get it? You and I are the same.”

“No,” Twilight shook her head. “I’m nothing like you! You're a murderer! You killed Pinkie Pie, Rarity, everyone! I’m going to stop you!”

“Hmm, you're a lot slower than I thought; guess we’ll have to start from the beginning.”

Twilight’s confusion grew as her double spoke. “What do you mean?” she asked, voice wavering.

“Did you think because you are an alicorn Princess that you’re invincible? That no matter what you went through, no matter what horrors you faced, you would come out the other side unscathed? That the magic of friendship would heal all? Ha ha ha ha. You really are a fool.”

“I … I don’t understand.”

“You don't really remember the time you spent in the changeling dungeon, do you Twi? Of course you don't, it was to painful. I wonder, do you know what happens to a pony when they experience more pain than they can handle, Twilight? Come on, of course you do. You were always a straight A student.”

“... The pony’s mind can fracture, leaving the dominant persona free to operate while the repressed persona deals with the pain being experienced.”

“Ding ding ding, we have a winner!”

Twilight fell silent for a moment as she attempted to process the information. Her double waited patiently, still grinning.

“So … you're saying that … I’m crazy?”

“Alright, finally we are on the same page! Although I'm afraid it’s much worse than that.”

Twilight shook her head, not understanding.

“Ugh, I have to spell everything out here. Listen Twi, pain is one thing. Pain is something you can work past. Pain doesn't necessarily make you kill. Problem is, changelings don’t just hurt your body when they take you. They feed on the love inside you, wherever they can find it. Whatever you love most. Like your spouse or…”

“Your friends,” Twilight finished.

Her double’s smile grew. “Exactly. We were in that dungeon for over a month, Twilight. A month. Those disgusting little worms crawling all over us, ripping and tearing at the love we held for our friends. By the time we were rescued, it was too late. Do you know what happens to you when your love for someone is constantly slashed and torn for such a long time?”

Twilight shook her head, eyes filling with tears.

Her double snarled. “It HURTS! That's what happens! Every time you look at them. Every time you think of them. Every time you touch that love held in your heart, all the scars are ripped wide open. It hurts so bad that you wish they were dead and gone so you could just forget them. Forget they ever existed and leave those scars alone.”

Other-Twilight stepped closer, face contorted in rage as she continued.

“But you never had to worry about the pain! About the hurt! Because I protected you! Because I took all that pain so you could continue having your friends. Your family. They needed you, and Equestria needed all of you together. So I took all that hurt and all that pain, and I kept in inside. But after a while it started to be too much, even for me. I started dreaming. Terrible dreams about them being killed. Killed by us. I wanted so bad to make the pain go away that I actually considered it. But I couldn’t do it. Because I’m you, which means I love them too. Just as much as you do. No matter how much I was hurting, I couldn’t bring myself do it.”

Tears were streaming down other-Twilight's face as she spoke, face still twisted in an ugly snarl.

“Then one day it was too much. I couldn’t take it anymore. I woke up one night while you were still sleeping. I walked out into the streets. I found a pony traveling alone, no one we knew. I lashed out. I took all that pain and all that hurt inside me and I used it against him. It was horrible. But after it was done and you woke back up, I didn’t hurt so bad. I could even have fun, enjoying the time we spent with our friends. Our family. But it didn't last forever. So I killed again. And again. I did it for you. I did it for our family. I did it for Equestria.”

Twilight stood, taking it all in. It made sense. It all made sense. “No … No!” she yelled, shaking her head. “If all that is true … If any of that is true, then why did you kill Pinkie? Why did you kill Rarity? They were our friends!”

Other-Twilight dropped her head, face filling with pain. “You don’t think I know that? I didn’t want this! It was your fault! You brought her into this! You saw her Pinkie Sense go off that night! You saw how she acted toward us! She knew! I had to do something before she blew the whistle! Nothing had changed, our friends still needed us, the people still needed their Princess, and Equestria still needed its protector!”

Twilight shook her head, trying to deny the logic. “What about Rarity?”

“Rarity crafted the lie detector. You saw it go off during Trixie's interrogation. What if someone else had been in the room? What if someone had seen the gem light up after you spoke and not Trixie? It was too dangerous. I had to make sure she could never make another one.”

This was too much to take in. Twilight shut her eyes and shook her head. “No ... No, no no no NO NO NO—”

“You killed Rarity?”

Twilight opened her eyes. Other-Twilight was gone. In her place stood the smaller form of Spike.

Spike’s face was twisted in angry determination. He spoke again.

“Answer me, Twilight. Did. You. Kill. Rarity.”

Twilight’s eyes lost their desperate anger.

“No Spike, you have to believe me! It was the other—”
The little dragon interrupted her by moving one claw from behind his back, revealing the brightly glowing fire ruby.

“How …” Spikes face fell he spoke, before rising back up in an angry snarl. “How could you!”

“Spike, you don’t under—”

Spike interrupted her again as he raised his other claw from behind his back. This one held a ripped piece of parchment. Twilight could clearly see the hastily scrawled message from where she stood. Twi is the killer. Send Help.

“No, Spike. Don't do it.”

He raised the parchment up to his mouth.

“Spike, please, no! Don’t do this!”

He inhaled deeply.

“NOOO!”

The two halves of Twilight Sparkle's torn psyche smashed back together and coalesced in one desperate act. It was a small spell, simple really. A version of the same one she had used to bind Trixie. But this one she wrapped around the snout of the little dragon as he attempted to breath out his dragonfire.

A loud boom cut through the early morning, followed by a sickening splatter as half of Spike’s face was ripped off in an explosion of contained green fire. His small form fell to the gore-strewn floor of the library; it twitched and writhed in pain and a dull moan emanated from his partially exposed throat.

“Spike! No!” Twilight screamed as she fell to her knees, a blood-splattered echo of her nightmares surrounding her.

Before she could process what her actions had wrought, she heard dulled voices from outside the library.

“That was Twilight! Sounds like she's in trouble!”
“Hold your horses there Rainbow, We’re right behind ya!”
“Guys, I … I don't think I can do this.”

Twilight panicked at the approaching sounds of her friends. Hastily, she jumped up and ran to the door to intercept them. Still several yards away from the library, the three of them stopped dead in the tracks at the sight of the blood covering Twilight’s coat.

Applejack was the first to act, taking a step forward. “Twi? What's goin on? The Captain rounded us up sayin Trixie was loose, but Rainbow went and checked. She’s still locked up.” She took another step, the concern in her voice being replaced with suspicion. “Where’s the blood from Twi?”

Twilight opened her mouth to answer, but before she could speak she heard a loud pained moan escape from behind her. Twilight watched as her three friends saw the mangled form of Spike crawl into view.

Applejack’s eyes hardened to steel. Her gaze was locked onto Twilight’s as she spoke. “Fluttershy, I want you to go in there and check on Spike. Do what ya can for him.”

Fluttershy, though clearly terrified, quickly took off and flew through one of the library’s open windows in search of her charge.

“RD, go get the Captain. Tell him to bring everyone.”

Rainbow looked as if she were about to take off, but stopped and turned back toward her purple friend, pain clear on her face. “Why Twilight? Why did you do it?”

Twilight opened her mouth to respond, but Applejack cut her off.

“It don't matter why she did what she did Rainbow. There ain’t no excuse, an’ there’s only one way to make this right.”

“What do you mean AJ, there has got to be a reason! Maybe she’s cursed or there's some weird magic thing goin on that we don't know about!”

Applejack responded with a snarl. “Well, what do ya say Twi? Were you under a spell when you killed Rarity? Or Pinkie Pie? Were you?”

Twilight opened her mouth again. She wanted to explain. To tell them of her psychosis. Of her pain. But all she could say to the Element of Honesty was, “No. I wasn’t”

AJ roared as she charged toward Twilight.

Rainbow Dash called after her, “AJ no, don’t do this! There has got to be another way! Something we can do to help her!”

Applejack ignored her, picking up speed as her powerful earth pony legs worked up into full gallop. Twilight stood her ground, eyes closed. She would accept what came.

“Applejack no! We’re a family! Don’t do it!”

As Applejack reached Twilight she pivoted on her front hooves, swinging her muscular hindquarters around and throwing all her forward momentum into her powerful back legs for a devastating kick.

“NOOOO!”

Twilight opened her eyes only to see a prismatic blur smash into the powerful earth pony in front of her. Applejack flew to the side and violently collided with the wall of the Golden Oak. A sickening crack was heard as her body immediately went limp and slumped to the ground.

Rainbow Dash sat flat on her haunches in front of Twilight, a lost look on her face as she turned it up to her purple friend. “... What … What did I just do?”

Twilight’s shock melted as her heart broke for her friend. She put a hoof on Rainbow’s shoulder. “You protected your friend. Your Princess.” She wrapped the other hoof around Rainbow’s shoulders and hugged tightly. “Your family.”

The Element of Loyalty looked up at Twilight, tears running down her face. “... What do we do now?”

“Let's go inside. We have to talk to Fluttershy. I have a lot to tell both of you,” Twilight said, helping the cyan mare to stand.

Together they walked back into the Library, only to halt suddenly, stunned by the sight before them. Fluttershy’s butter-yellow coat was covered with a shower of blood, a heavy tome held in her front hooves. At her feet, the lifeless form of Spike lay, head smashed completely to a pulp, sprays of gore covering the floor and shelves surrounding him.

Fluttershy looked at the other two ponies, tears flowing like rivers from here eyes. “Rainbow, Twilight … He … He was hurt so bad … I couldn’t … There was nothing I could do to help … the noises he was making … I had to do something, I couldn’t just let him … Oh Celestia, what have I done? What … What am I?”

Twilight stepped toward the Element of Kindness, the sadness she felt for her friend filling her voice as she spoke. “You’re family, Fluttershy.”

Rainbow Dash walked up to her yellow friend and wrapped her in a comforting wing, her own tears forgotten as she wiped Fluttershy’s away.

Twilight couldn't stop the warm smile take hold on her face as she looked at her two friends. “We’re all family. We’ll figure this out. We are together now, That's what matters.”

Author's Note

The final chapter! Please let me know what you think of the story in the comments, all thoughts are appreciated!

*Note, while this final chapter completes the story, I do plan on writing a short epilogue in the near future, so keep an eye out!