What ties a ghost to the earth? Most people alive do not know, and those who are ghosts certainly don't know it either. No ghost in living (or floating) memory had ever managed to pass on…
But the reason is simple: a soul is tied as a ghost to the earth by unfinished business or grave secrets which can not be lost.
The Hogwarts ghosts were no exceptions to this rule… and the Great Battle had finally brought at least a couple of ghost-y souls to the light.
How?
Harry and Hermione had begun writing down the history of their hunt for Horcruxes… and naturally, details had spread far before the planned release date of their memoirs. And with more and more people knowing about the injustices that had taken place, the force that held Myrtle, the Grey Lady and the Bloody Baron bound to Earth began to lessen.
The Chamber of Secrets had been thoroughly cleaned up – a lot of people seemed to know barely enough Parsel to open the secret entrance in the toilet, and so Minerva McGonagall, new headmistress of Hogwarts, decided it was too dangerous to leave the place as-is – highly poisonous Basilisk fangs and body parts were scattered everywhere, not to mention the structural damage inflicted years ago when a certain Mr. Gilderoy Lockhart tried to use a memory hex with a backfiring wand.
So during the reconstruction of Hogwarts, the chamber was turned into a memorial site, to remind visitors of the death of Moaning Myrtle and the treachery committed upon Hagrid by Tom Vorlost Riddle, better known as Voldemort.
Professor McGonagall had commissioned a golden plaque to be hung on the wall of the toilet room. It read:
On June 13th, 1943, the Hogwarts student Myrtle was murdered in this lavatory by Tom Vorlost Riddle. She was forced to exist as a ghost until her murder case was solved by Harry Potter, Ron Weasley and Hermione Granger in 1993.
It was installed in a private ceremony attended by the Hogwarts staff as well as Harry, Ron, Hermione and Ginny.
Myrtle hovered directly in front of Harry and said: "Thank you, Harry. I have never expected anyone to release me from the bound anchoring me here."
And she faded into the light, never to be seen again.
The Bloody Baron and the Grey Lady, however, chose another way.
A couple of months after Myrtle moved on, the Bloody Baron summoned all ghosts of Hogwarts to the very same dungeon in which Nearly-Headless Nick usually held his deathday parties.
"My friends," he began, shame written all over his silvery face, "I know it is most unusual of me to talk with anyone, let alone invite everyone to what must be the first full ghost gathering since the Great Battle."
He had never bothered to tell the other ghosts why he wore heavy chains and sported bloody clothing. And so everyone was hooked.
He looked straight into the dead eyes of Helena Ravenclaw and began: "Nearly a thousand years ago, I have committed an act of murder. I have slain a woman I have loved, and this is why I have been wearing these chains ever since."
The Grey Lady immediately knew what he was up to, and she remembered what she had heard Harry Potter saying in the Great Battle: "Think, and try for some remorse…"
"Indeed, as you should, after what you have done to me. But then again, I am not flawless myself. I have betrayed my own mother. I had stolen her famous diadem. I had run off to Albania with it," she said slowly, sentence after sentence.
"And I managed to track you down. I let my feelings overwhelm myself. I took my own life, with the same weapon I used to take yours. And to make it worse, I never had the courage to tell anyone, not even your mother, who sent me, what had happened. She passed away without ever seeing either of us again. Can you forgive me, my love?" he asked.
"I do forgive you, but you must know that I still do not love you, Waldo," she replied.
The Bloody Baron, or Baron Waldo, only nodded. He had not expected this to ever change, even if he had hoped.
"Peeves, you are the only one being capable to interact with the castle. Please, find a portrait of Rowena Ravenclaw and bring it here," he said, visibly anxious. He felt that something had changed.
Soon after, Peeves returned with a portrait – which he had nicked from McGonagall's office. In fact, this was the only portrait existing of Rowena Ravenclaw, for every other reproduction of her had been a statue. And no ghost except Peeves, who did not care about any rule, had ever set foot in the Headmaster's Office.
"So," the picture of Rowena said, "Peeves has told me that you two have something to tell me?"
"Yes, mother," Helena Ravenclaw whispered. It was the first time that the shadows of her and her mother had ever seen each other, much less talked.
"I was the one responsible for the theft of your diadem. I had thought it would make me wiser, and yet it failed doing so. I have betrayed you," she said.
"As I did. I have failed in my task to bring back Helena and the diadem. I have murdered your only daughter out of rage," he confessed to the portrait.
"But after all these centuries, I am able to forgive you. Both of you have done your time. I can only ask you to come into the light. Helena, my daughter, I miss you," the portrait of Rowena Ravenclaw said with a warm voice.
With this, the Bloody Baron and the Grey Lady faded away, their sins finally absolved and forgiven. The remaining ghosts just stood before the empty portrait, awestruck by the events they had witnessed.
A/N: Back from the dead - my old account ms91 got eaten by the "plus-sign" ban... if anyone wants more loose ends of the books tied up (I'm especially thinking of the minor characters like Kreacher!) or if you like this one-shot, please leave me a review. Thanks!