As the bloody war raged on, Equestria fell deeper and deeper into despair until it was but a pale imitation of its former self. Gone were the vibrant colors and the joy, leaving only the darkness and grim determination of a people at war. Many yearned for peace, to return to the days of harmony, but there could be no peaceful outcome to this war. They fought for survival, for their very lives, and their continued existence hung upon the outcome of this conflict. There could be no going back.
During the darkest times of the war, when hope had gone and the sound of laughter no longer rang through the streets, a lone mare stood against the silence. None had listened when the pink mare spoke of a battle to be fought here in the streets of their cities, and even in their very homes, but she came anyway. None had believed in the threat she claimed to see, and yet she still stood against it. Alone or not, she would stand. Her foe was not the enemies of Equestria, but the building gloom in the hearts of its people. She fought not with sword or magic, but with the warmth of her smile, and the laughter in her heart.
The nation's armies could not see what was so plain to her. They fought so hard to save everyone, yet they could not see the slow deaths all around them. But the pink mare did, and so she fought to save the things that she knew /truly/ made Equestria what it was. She knew It wasn't land or borders that made a nation, but its people, their hearts and minds. So she fought, for the joy, the love, the laughter, all the things that would truly kill them if they were lost.
The pink mare moved through every town and city in Equestria, never stopping, never resting, forever fighting her personal war. Some might have thought her mad, fighting a war all alone against an unseen foe, but results speak for themselves. Whether it came in a party, a smile, a joke, or even just a shoulder to cry on, joy and hope came with her. Street by street, door by door, the pink mare drove the gloom from the hearts of Equestria's people, and with every smile, the tale of Pinkie Pie grew.
It was another thirteen moons before Equestria's war finally ended, but after sacrificing so much, they finally stood victorious. The victory celebrations were spectacular, and the joyful cries of the people filled the air across all of Equestria. The speed with which Equestria's people felt the joy embrace them, and the ease with which their laughter returned, did not escape them. It was only now, after the war was finally over, that the ponies of Equestria realized the true importance of what Pinkie had done. She had kept their spirits alive, made them remember how to laugh, how to be happy, how to /live/ rather than simply survive.
Pinkie was a true hero, and was to be honored as such, but not a single pony had heard or seen her in over a week. The princesses immediately started a massive search and put Twilight in charge of finding her friend and Equestria's savior. Not a single pony spared even a minute to take off their armor before setting out to search. But in the end, it didn't matter, it didn't take long to find her.
Twilight's unit was flying over a sparsely populated section of Equestria, between Canterlot and Manehattan, when they spotted a pink figure on the road. Only a day after the search had begun, they had found Pinkie Pie.
Twilight landed next to her friend and gasped. The pink mare was filthy and emaciate, and her back hoof was twisted at an odd angle. Rushing over, Twilight knelt at her friend's side, rolling her over and taking her in her arms. She seemed to weigh no more than a feather, and her eyes were hazy and unfocused, but she was alive. It didn't matter what happened later, right now, she was alive. Twilight had been on the verge of tears, but she held them back now as best she could as she cradled her friend. "Pinkie, wake up! Please! Pinkie it's me, Twilight! Celestia and Luna sent me to find you. You can come home now! The war is over, /your/ war is over."
Pinkie's hazy eyes seemed to focus ever so slightly as she heard Twilight's voice. A small smile crept very slowly across her face as some distant part of her mind registered Twilight's presence. Her cracked lips parted as she tried to speak, but only the faintest semblance of a whisper escaped.
Twilight leaned in closer to her friend, trying to catch her fleeting words. "I don't understand Pinkie. What are you trying to say?"
With visible effort, Pinkie took a ragged breath and spoke again, her halting words still barely a whisper. "Twi... light... d... did... we... win?"
Twilight simply couldn't contain her emotions anymore, and several tears slid down her face as she nodded her head, to overcome to speak.
Pinkie's lips cracked even further and a small bead of blood rolled down her chin as she smiled up at her friend. She forced in another ragged breath, but her voice was fading now and Twilight had to lean even closer to hear her. "That's... good..." Pinkie's eyes lost what little focus they had and slowly glazed over; her body grew limp, and with a soft sigh, Pinkie Pie, hero of Equestria, died.
Twilght held Pinkie close and began to weep openly, trembling with her grief as she cradled the lifeless body. She hadn't thought it was possible for someone so warm, so full of life, to suddenly feel so cold. Her tears fell onto the pink mares cheek, carving paths through the dust as she spoke to her friend, saying now what emotion had not allowed her to say earlier. "Yes Pinkie, you did it. You won. The armies saved our lives, but you saved our hearts." She clutched her friend's body tighter now, afraid that if she let go, this nightmare would become reality. "Thanks to you, Equestria still has joy. It can still laugh. Can you feel it Pinkie? The joy and light all around us? Can't you hear the laughter?"
Twilight's soldiers gathered around her and placed sympathetic hooves on her shoulders and arms. She was too grief stricken to protest as they gently pulled her away from the body. She couldn't even bring herself to stand, and could only sit, weeping silently as she watched them wrap Pinkie's body for transport.
Pinkie's body was taken back to Canterlot, where Luna and Celestia decreed she be given a heroes funeral. Her body was cleaned, her hair was combed, and she was clothed in a simple pink gown before being laid out in a private room while preparations were made. Twilight, Applejack, Fluttershy, Rainbow Dash, Rarity, and Spike, were allowed this time to say goodbye to their friend in private. Each silently cried as they made their peace, silently filing out one by one to join the princesses until only Twilight remained.
Moving to the side of the bed, Twilight forced herself to look down at Pinkie. She didn't want to accept her friends death, but she knew she had to. "I guess this is the end..." She wiped away a tear before leaning in close and gently cupping Pinkie's head. Closing her eyes tightly to keep from crying further, Twilight whispered a few final words to her friend, hoping that somehow she could still hear her. "Thank you for saving us."