I know something is wrong when I can't even feel pain.
Everything is cold. There's nothing but darkness around me.
No signs of your colorful mane, no signs of your gleaming magenta eyes that matches the glow on my horn. Not even the tiniest speck of blue that pointed to your coat.
I refuse to believe you broke your promise.
"No, she didn't."
You said I will always see the light around you. You said that with you, I'll never be in darkness again.
Most importantly, you said that you'll never leave my side.
"It's none of her fault and you know it."
You are not the Element Of Honesty, but you're a walking representative of loyalty. You will never break something like that to me.
"But don't worry, it's not yours either."
It won't shut up. Every day, I have to fight this voice. This voice that won't go away. This voice that finds me in the darkness. This voice that always reminded me of you.
"She's gone."
No, you are not. This is nothing but a nightmare, a twisted perception of reality that finds me every night. Maybe there's something wrong with me.
"Of course there is. Stop pretending that there isn't."
Maybe I should see a doctor. Or take my friends' advice and get out more. Even though the storm outside is raging relentlessly. I feel the fear, the sinking feeling dragging me down, deeper into the darkness and locking me within myself. I was scared, but I couldn't feel - I couldn't smell the rain or hear the flashing lightning - I could see nothing.
"Afraid of the truth, as usual."
Every night, storm or not, it was the same. This darkness, this tormenting voice, this numbness, this fear. A fear that I could not name.
"Or dare not name."
But I would always turn around and reach for you whenever I feel afraid. It doesn't matter that I know you will tease me for being the scaredy-cat that I sometimes am, I feel safe in your embrace and I will always seek it.
"Yet, you will always reach out to emptiness."
I know you're not always there, not when I sleep. You always return late, especially when you have Wonderbolt shows scheduled. I'm used to sleeping alone, but I know you're always there, even in the middle of my sleep. I would involuntarily still reach for you in the deepest of slumbers, and I'll always smile knowing you're there.
"But now you're met with tears every time you connect with nothing."
You're still here. I know you must be. I feel your presence, in my heart if not within my sight. I've learned a long time ago that just because you can't see something doesn't mean that it doesn't exist.
"But you're right this time."
I know who she is. She calls my name, every day, every night, every time I'm alone. She finds me in this never-ending sea of darkness, and she calls my name. I can't bear to see her anymore, but I know she's always there, silently watching me, silently taunting me.
"You're just like me."
Indeed. I look like her. But I'm not her. We might look alike - completely alike, even, but we are not one. She isn't me. She looks exactly the same as me, but she isn't me. She is just some spirit, some lost whisper in the past that decided to haunt me.
"You're even more stubborn than her."
I've tried, believe me. You've not shown up at all these days. It's hard to face this darkness alone, believe me. I want nothing more than you to be in this bed, beside me, right now. Where it's just a silent, tranquil night for both of us, with the light of Luna's moon illuminating our coats as we snuggle against each other.
"But you know it's something you will never get."
Studying wasn't helping me. My mind that once worked mathematics and science equations in a blink of an eye refused to function whenever I try. I tried reading too, but it doesn't work either. It always did, but not this time. I can barely read a few lines every time I try, and it usually ends with me just giving up, falling into this darkness again.
"Maybe that's because you can barely read two lines without getting your vision blocked out by tears."
Rarity had suggested that I read romance novels. The idea of me drowning myself in pages of emotions wasn't unbearable. In fact, it was one of my favorite pastimes whenever I'm feeling particularly down or stressed. It's even better than studying. But somehow, the idea of reading something out of one of my favorite genres did not sound appealing to me.
"Of course, it just reminds you of her."
Pinkie Pie, being herself, of course, decided to help me in her own way - the partying way. I accepted her first few invites, and don't get me wrong - I was truly thankful for her as she even arranged these events to be private between our very close friends and no one else, but I just couldn't go on without feeling like something's missing from those parties. I hated to decline her invitations, especially when she is only doing it for me, but I couldn't bring myself to go.
"Of course. How can a party ever be the same without a little Rainbow?"
Fluttershy was even quieter than usual, which should be a clear sign that something was wrong. She would often come to my castle and offer me nothing except the comfort of her presence. I can't say she failed - in fact, she chased away the loneliness and dark clouds that came into my way at first. But eventually, every time she came and sat beside me, I couldn't see anything except this darkness again. Even when I manage to look at her for every once in a while, I feel like I'm still alone, like a homeless pony out in the winter, as the dark clouds became too thick to dissipate. I hated to disappoint her like this. Comforting other ponies in silence was usually what the pegasus was good at, but this time, even when I manage to pay attention to her eyes, I knew she was distant, too. I didn't know when she stopped coming, but I didn't blame her for it.
"Yeah, of course. Every time she comes, you see a different pegasus.
Applejack didn't say much either every time I met her. I knew she didn't want to say anything that hurt me. She knows how honest she can be, and I know she just wanted to avoid saying possibly hurtful truths that I couldn't accept. I know she wasn't happy either, the last time I saw her.
Of course. But if only you were as honest as she is."
No matter how hard I try, I can't push this darkness away. I can't push her away. No matter what I do, I always end up in the same place, in the same darkness where I couldn't feel anything except fear. Fear and possibly diminished emotions trying to break through.
"You really should let them."
Every day, almost every hour, she calls me.
"And I have no intention of stopping."
I never gave in to her, but I cannot help but slowly feel myself losing control.
"Not until you accept what is it."
I don't know what is she rambling about. To prove her wrong, I focused my energy to my horn and created an orb of light. I'm most certainly not grieving, not upset, not mad, not tired. I'm still the Princess Of Friendship. I'm still standing here, standing strong and ready for Equestria. For everypony else.
"But not for yourself."
There's nothing wrong with me. I'm a princess, and princesses get stressed often. Even Celestia admits to have times like this in her life. And I have a wonderful life, although nowhere as long as hers. I have wonderful friends, I have amazing adventures with them, I have the best marefriend a pony could wish for...
"A marefriend that's no longer here."
I have nothing to complain about.
"Yes, you have."
But where are you? Oh, Rainbow Dash, just where could I find you right now when I need you?
"Maybe you start by finding yourself."
Who am I kidding? I'm driving myself insane. Every second this darkness goes on, I lose a little bit more of myself. I'm surrendering part of me to her. She's infecting me, pulling me farther and farther away from the real world and the warmth in the world. She's taking over me, dominating my senses completely.
"Twilight Sparkle."
My magenta glow illuminated a small area around me, but I could see nothing but darkness around me. I refuse to meet the purple eyes above me, despite my light shining off her lavender coat.
"Twilight Sparkle."
No. I will not give in. I will never, ever give up. I know you're there. You're keeping your promise. You're still lighting my way, even though I can't see you and I can't feel you. I have to break through, I have to -
"Twilight Sparkle!"
"SHUT UP!" The words finally burst forth from my mouth as I roared in anger at the nothingness around me. I know she stepped back, her face not betraying her emotions. I always hear anger, sarcasm, disappointment and perhaps even pity in her voice, yet she shows none of it on her face.
And as if all the walls I've built around me just crumbled, I felt my tears as the heaviness in my heart finally settled down, hitting me at full force as a cry of agony tore from my throat.
And she just watched.
She watched as I lost control and broke down in tears. I couldn't imagine what lied behind those purple eyes. They were the exact same color, shape and form as mine, yet it hid the mind of a totally different pony. They were cold, unflinching, emotionless, unlike anything you ever said about my eyes.
I wish you would say that to me again.
"Twilight... please." That was the first thing that she ever said that contained any emotion at all. And the tone of her voice - it truly sounded like me for once. That is, if I was speaking, I would sound like her - dry, hoarse and full of suppressed pain.
"Look at yourself. Closely. For once."
I looked up, my eyes still blinded by my tears. I didn't obey her instructions - not exactly. I looked at the alicorn standing before me. I realized I never noticed her disheveled mane and tail, her coat that now only gave off a dull glow as my magenta aura hit it, and her eyes that I always deemed emotionless that were now filled with sorrow and exhaustion.
"Please. Answer me honestly. What did you promise her, exactly?"
"I..." The voice that came out from me barely even sounded like a whisper. "I promised her... that I'll always find her. That I'll always be with her in the end."
"No," the other alicorn replied, her tone void of the cold, emotionless feeling it once held, replaced by an endless ocean of despair and pity. Probably self-pity. "No," she repeated. "The exact words you said to her."
The exact, cursed words I could never forget. "I promise... I will always end up with you, no matter through life... or death."
The stinging feeling in my eyes and chest returned immediately after I said that. I didn't want to hear what she has to say, I didn't want to see her anymore. I wanted to just disappear, become part of this darkness, and stay in eternal silence forever.
I don't belong here.
"Tell me... why are you crying, then?" Her voice didn't even sound depressed anymore, just plainly tired. I didn't want to look into her eyes. I kept them shut, barely whispering,
"Because..." The truth struck me, as if I got hit with a deflected magic blast that I shot from my horn. "Because I knew... when I made that promise... I know I'll..."
I finally identified the source of my fear.
She was right. I was indeed afraid of the truth.
"Because I knew I'll never be able to keep that promise!" I yelled, through my tears and with my broken voice, a voice that didn't belong to a princess. It belonged to a lost mare, a mare that could not cope with this level of loss, the mare who could not accept the fact that she was cold and alone, with no one beside her, could not accept the fact that her marefriend was... was...
"She's dead." I knew I didn't speak those words, yet it sounded like we both spoke in unison. Although my voice and hers sounded the same, I knew they were different. I knew I didn't speak, but those words came out of me.
She was right. You are dead. You're dead, Rainbow Dash, and you left me alone. You broke your promise, just like I have broken mine.
You are gone, and I could not see your light anymore. The light that only your magenta eyes can carry, the light that shone even brighter than the sonic rainboom you created a few years ago. The light that cannot even compare to the one from Celestia's sun.
And I know, I will never be able to find you again. I will never be able to keep my promise, I'll never be able to reach you at where you are, ever again.
Because I'm an alicorn, an immortal. A pony that carries both a curse and a blessing. A pony that was destined to watch as her loved ones all fall down and leave, until only she remained.
"Twilight. Look at me."
She spoke again. This time, I dared to look up. I broke the chains that had held me back from the truth. The devastating truth I couldn't accept. I saw her, this time extending a hoof out to me. I didn't know why, but I did not hesitate to take it.
But once I touched her, her whole form rippled, as if I disturbed the calm surface of a lake. I flinched back, afraid that I've done something wrong, but the alicorn just smiled - a genuine expression matching her eyes carrying bittersweet emotions, before she said:
"You know the truth now."
And I knew I said those words as well as she did.
I didn't watch her leave. I knew where she went. I knew it, all along.
She wasn't my enemy. She was never even real. I wasn't haunted. At least, not by her.
I'm indeed lost, grieving and drowning in depression, bleeding from a wound I could not heal, not wanting to face the life that lied ahead of me, knowing that it'll never end and that I'll never see you again. Knowing that neither of us could keep our promises, despite what we've been through.
I can no longer go on pretending that I'm fine.
Because I know I'm not. I may be an immortal, but this is what I couldn't fix, what I couldn't change for the better. From the day we became a couple, I knew that you would leave me one day, to a place where I could never follow you to. When I made that promise, I knew I messed up, that I did something I could never change.
Maybe it is alright to cry. Maybe it is alright to mourn for you.
Maybe I should release myself.
And tonight, I did. The darkness around me disappeared, as if it was never there at the first place. The night sky after the storm was filled with stars, no doubt a special creation of Luna's. I can finally breathe again. The truth hurts - it probably would never heal - but the pain somehow was less.
And maybe - just maybe, you haven't broken your promise at all. Of course, a brighter star in the sky could always be another one of Luna's constellations, but I know, somehow, that you were still calling me. Your star still shone brightly in the sky, and I might be seeing things, but the colors of a rainbow flashed briefly before my eyes as the star sparkled.
Maybe I was just too blind. Maybe you never broke your promise at all. Maybe it doesn't even matter if I can keep mine or not, because you will still love me all the same, just like what I would do to you all along, and will still do for the rest of these years.
I will not promise you anything, but I'll never lose myself again. Not like that.
Because maybe, even after all this while, no matter how much pain I'm in, no matter how many mistakes I've made... you will still always light my way.
-END-
Author's Note
It's been a while since my last story, and I hope you all enjoy this little TwiDash I managed to come up with! I can't seem to get rid of my addiction to sad story writing, welp. 
Anyways, I have scheduled two upcoming stories in the making - one about a certain unicorn pony, the other about two princesses. If you are interested, please stay tuned!
