Some of the castle's ghosts seemed to have fought during the Battle of Hogwarts. Though as ghosts it is uncertain how much effect most would have on the physical world apart from startling or giving the chills. Peeves is a rule onto himself.

Ghosting Along

Myrtle peeked out from the tub of the Prefect's Bathroom.

Blaise Zabini and Pansy Parkinson. The young man had his shirt off and his prefect companion was doing something to his back she could not quite see. Naughty, naughty… hiding out there instead of being at the Halloween feast… This promised more fun than Nick's Death-day party.

"Ouch! Careful there, Pans!"

"Do you want the blackheart thorns out or not? Or you can go to Madam Pomfrey."

"How's Greg doing?"

"Still in the infirmary. His body is back but his brain still thinks he is a pumpkin. The matron is just waiting for him to remember how to stand up and walk out..." Pansy leaned close to Blaise's ear.

Time to make her move… The ghost girl leapt out of the tub, sending soapy water splashing over the pair.

"Blaise and Pansy sitting in a tree, K-I-S-S…" she sang.

"Pest!" Pansy shrilled as she grabbed her wand. The hex just shot through the ghost with barely a tickle. Two buckets of ice-cold water were dumped on the hapless pair by a crackling Peeves. Blaise grabbed his shirt. The beleaguered students beat a hasty retreat.

"Oy, Myrtle! Sir Nicholas is looking for you in the West Corridor! His Bloodiness is with him!"

Muttering, a grumpy Myrtle dove into the pipes.

"He's wearing your House colours, you take him," the Bloody Baron growled.

"He's been hanging about near your House common room, you take him," Sir Nicholas protested. "I can speak to the headmistress about his Spirit registration, but I know nothing about dead children…"

"And you think I do, man?" the Baron snapped and shook his chains. "It's all that wretched nun's fault! Hides him away for weeks then drops him on us at the first party we hold."

"Do you think he has been Confounded? Six months floating about without a word to anyone but the Silent Sister. Maybe he doesn't know yet. Old Binns hasn't even figured out he is a ghost even now… Someone must tell the lad…" Sir Nick looked pityingly at the newest ghost.

Myrtle peered at the new ghost. He had silver-pale hair that might be brown or blond in life and wore Gryffindor colours. He had a goofy smile on his face as he waved his camera about. He seemed to be younger than Potter or Draco, and small for his age. He drifted in and out of the windows, apparently taking photos of the grounds.

"Ah, Miss Warren, perhaps you might be able help us seeing you are the closest in age to Master Creevey…" Sir Nicholas shot her his most charming smile as his head hung lopsidedly off his neck.

"I was hoping to get a photo of Harry when he bests You- Voldemort," Colin was all bounce and excitement. "I had my wand out. Then someone threw a curse at me, didn't feel a thing… I just kept running, until I ran through that giant… Some nun grabbed and yanked me into the dungeons. Afterwards, we just waited until all the fuss died down and I realised I was a ghost. How long will I be stuck here?"

"Forever, or did you not reach that chapter in your DADA textbook yet? Pity you didn't see who killed you… They might let you haunt them a bit if it's a Death Eater…" Myrtle rolled her eyes. Colin had been sneaking in and out of the common rooms and hidden passages in Hogwarts with his camera, taking photos no living being would see for the past months. Colin seemed to cut of the same cloth as the Fat Friar – cheerful and optimistic to the point of exhaustion.

"I cannot find Harry or my brother Dennis… Has School started yet?"

"They might not have come back this year. The Fat Friar said half the places were empty during the Welcome Feast. Fewer first years too."

"Will they allow me to go speak with my mom and dad?"

"Wouldn't work if they are Muggles. They won't be able to even sense you. And besides, the Ministry will come down hard if you leave your designated haunting place without permission. Myrtle's Law. I know, my bad. Went a bit overboard dropping a wedding cake on Olive. Since you died here at Hogwarts, you are stuck here."

"Did you ever try to leave?"

"Got as far as the lake after they slapped the wards in place. I haunted Olive Hornby for a while before that - all the way to London. She used to pick on me before I died, you know. The first two times you get warnings for unauthorized haunting, if not malicious. The third time, they would stick you in a mirror and lock you up in the Ministry basement. If the haunting is malicious, it is straight to the mirror," Myrtle explained.

"So where do we hang out when we are not haunting? I got into all the common rooms over the summer, but I think they renewed the wards. I cannot get in now," Colin perched on the windowsill. "Not even into Gryffindor. The Fat Lady would not let me through the door even with the password."

"I have my bathroom where I died. Do you prefer to hang out outside where you died? Or do you have a favourite place when you were alive? There are some rules to follow – no bothering the staff and students, well, too much. Only Peeves has that honour. You must listen to the headmistress, professors, and House ghosts' orders. It is fine if you make friends with the students, but they all go away in the end." Myrtle shrugged. Potter and Malfoy never returned for their repeat year. She saw the Weasley sister and Hermione, but she was never close to them.

"Are you going to be my ghost mentor or something?" Colin asked.

"I suppose. Sir Nick did ask me to guide you. You were the only one who did not cross over that day… Have you spoken to any of your friends yet?" Myrtle arched a brow.

Colin shook his head. The wind seemed to have gone out of him. It seemed his new existence as a ghost was sinking in. Wordlessly, she hugged the younger ghost. No one had died in Hogwarts after her until Harry Potter's arrival. She did not care for the creepy Professor Quirrell. Good riddance. Cedric was good-looking, but he did not return as a ghost. She had been hopeful when Draco got badly cut up in that duel, but one never could tell if he would turn into a ghost. All that blood looked both painful and messy. She went screaming for help instead. He survived, but never came back after the battle. At least it was the two of them now…

"Hullo, Myrtle. Hullo, Colin. Mind if we come in for a bit?"

Luna popped her head into Myrtle's bathroom. With her were a pair of fourth year Slytherin girls and a tiny Hufflepuff boy. "There is a Swooping Evil loose and we need somewhere safe to hide until Professor Rolf catches it."

"Come on in, Luna," Colin cheerily waved the students in while Myrtle started moaning about not finding any peace.

"Thanks, Colin. Here, have some chocs. They have been sitting in my old school trunk since I was snatched. Mrs Malfoy just had the trunk sent back to me at Hogwarts," she tore open the wrapper of a mouldy-looking candy bar and left it on the sink. She summoned a fuzzy-looking lump.

"There is raspberry cake too but not sure if it's to Myrtle's taste."

"Thanks, Luna…" Myrtle's scowl changed to a smile.

Author's Notes:

In some traditions, the ghost in the bathroom is a bloodthirsty little devil all too ready to drag you into the afterlife. Myrtle did display some mean vibes at times, but she was ready to provide a listening ear to Draco in his sixth year. She proved herself helpful to the Trio during their time at school. Presumably, she is still haunting the bathroom.

Of the fighters who perished in the battle, the most likely candidate to have unfinished business is Colin Creevey. So yes, he is stalking the halls with his camera hoping to capture that elusive photo in this fic. There is no canonic proof that anyone who died in the Battle of Hogwarts returned as a ghost.