After reading YAJJ's fourteen, I wanted to try to write something like that too. It's very similar, so sorry about that, but it was written in just two hours so cut me some slack... Maybe I'll upload the original Dutch version later; who knows? That version is also in third person, if most of you prefer that then I'll adapt this.
You are fourteen years old. Your best friend encourages you to check out the new portal from the inside. How could you deny? After all, ghosts don't exist anyway.
You found out how wrong you had been. In the past five years, you've fought the dead on a daily basis. But slowly you've started to realize that more has changed to you, than just an addition of ghostly powers. While you watch how your friends grow up, enter new relationships to break up again, you stay small. Your parents convince themselves it's just a rare illness. You're just late, you'll grow eventually, right?
After keeping your silence for five years, you finally show Jack and Maddie the truth. And for the first time in those years you let all your worries slip away. You, the 19 year-old 14 year-old cry while you let yourself being hugged by your parents. They promised to never leave you.
You didn't go to school anymore: you can only sit through a lesson so many times before it literally begins to make you sick. Plus, nearby high schools had started getting suspicious, and rumor had it there was a 14 year-old who claimed to actually be thirty, and to already have his certificate. That was what you told Tucker also, when one day you stood on his doorstep, and offered to help take care of Ben, his two-year old.
It was true. But what was most true of all, was what you didn't tell him: you are lonely. Jazz had left Fenton Works ages ago, and though she visited as many times as possible, it was still not enough. Maddie had died a few years prior. After that, Jack had barely spoken a word. It didn't surprise anyone, but you, who still are so horribly full of energy, couldn't stand watching TV in silence anymore.
Sam went around the world by now, as an animal rights activist (and ghost rights, though that didn't seem to go as well). So Tucker welcomed you with open arms. He also had some need for company, since his wife had left him a year-and-a-half ago.
But after a month, Tucker told you he really needed to get back to work harder. And of course he trusted Danny, but he'd rather leave Ben with someone who wasn't constantly attacked by ghosts, you would understand that, right? So you left.
Even though not a single ghost had dared to attack you in at least seven years.
You said goodbye to your father for good, while the wooden chest was slowly lowered in the ground. That was also the last time you saw Sam in the flesh. She had coincidentally been in the neighborhood, when the sad news reached her. Your reunion didn't get past an awkward 'Hello', before Sam joined the other adults.
Ben pitied you, and laid his hand on his father's friend's shoulder, who by now looked four years younger than himself. You wish not for the first time to join your parents in death.
After that, you start roaming. You attempt to find Danni; She's also a ghost, partly, she has to be there still. You secretly long to see the same pain in her eyes, which you've known for far too long: the realization that you're stuck.
Until Clockwork finally tells you that the 'young' clone's labile ectoplasm already failed after a few years. She'd left this world even before Maddie had.
You don't forgive yourself.
Finally you've gathered the courage to end it permanently. On the edge of the platform you waited, before you threw yourself at the front of the supersonic train. For a moment you feel immense pain. Then everything goes black.
The doctor claimed you were incredibly lucky. Though you had been hit frontally, you appeared to have relatively little wounds. Joking she said it seemed as if all your injuries had healed at the spot, if such a thing had been possible. Who your parents were, she asked.
Tired of lying and hiding you told her your entire story. The woman laughed warmly. Ghosts hadn't been seen in fifty years, and Phantom hadn't been spotted for even longer. She advised you to talk to a psychologist.
That was exactly what you were planning to do, you answered, before transforming in front of her and flying to the retirement home where Jasmine stayed.
Jazz looked up surprised when a familiar teen flew without knocking into her room. She said jokingly that he hadn't aged a day, and you laughed. When you looked each other in the eyes you both knew that you'd rather cry.
But Jazz stayed strong for you, and what else could you do for her than to return the favor?
The nurses wondered who could be the young guy, who sat through the funeral in outdated clothes. For as far as they knew, Miss Fenton didn't have any family left, except for her missing brother.
But he was so impossible to find that his mere existence was dubious.
You don't have the energy anymore to keep up with Tucker and Sam's lives. You allow yourself to slowly forget them, only hope that they died peacefully in their sleep. You wallow in your own sadness.
Vlad had died a month ago. The ecto-acne had unexpectedly returned. When you found out, you hurried to your old nemesis' deathbed. You were just too late; and since ground was scarce, the old man was cremated.
The urn was angrily thrown against the floor of the mausoleum. Green-tinted tears turned the ashes to a muddy mess.
You dragged yourself back to Amity Park. The small town was now abandoned. A deadly silence hung between the ruinous houses, left because of the spirits. Amity Park was, literally and figuratively, a ghost town. You laugh hard and humorless at the irony. The sound echoes through the streets.
The way to the lab is still engraved in your memory. A musty smell hung in the old room, and it wouldn't surprise you if there lived eight generations of vermin now.
The portal stood still against the wall. Paint was peeling from the once striped doors. Now, they were a rusty brown.
You easily pull the doors apart. The portal must've been turned off in the course of the years, but that didn't matter. You only had to turn it on.
You screamed in surprise when hundreds of volts mixed with ectoplasm ran through your body. Had it hurt this much, a century ago?
Shivering you open your eyes. Apart from the again working portal, the lab was still the same. But you felt an entire world of difference. The ice cold floor sent chills through your spine, and you were shaking with excitement. Ghosts don't feel temperature.
You grabbed a piece of glass from a long gone project. Sharp, long and pointy, it was perfect.
Without hesitation or doubt the shard was forced through the beating heart. The pain was nothing compared to the heavenly blackness embracing you. You felt everyone's presence around you: Maddie, Jack, Jazz, Tucker, and even Sam. 'Welcome,' they greeted as one. Tears rolled from beneath the shut eyelids.
'I missed you so much,' you whisper, but in the enclosed space it sounded like a crowd.
'We've never left you,' you hear, and before you could wonder if it was real or you nuts, the dead body drops on the floor.
In the green light of the portal, the blood had an eerie glow.
Tadaaaaaaa *waves hands* I know I'll just go back to my other stories. You should just read the 'original' from YAJJ. I'd link it but FF doesn't like that.