QLFC S11 R4, Catapults, Keeper, prompt: Write about the end of a romance changing someone for the worse. It must contain a ghost as a main character.

Word Count: 2978 (according to Gdocs)

Warnings:

Canon divergence; tragedy.
Dark Helena.
Major character deaths (Baron, Helena, OC) — death caused by an Unbreakable Vow, and murder/assisted suicide (Helena asks the Baron to kill her).
Obsessive behavior from the Baron towards Helena (jealousy, unrequited love) and from Helena towards the diadem and OC after OC's death.
Mild necrophilia (Helena wanting to revive OC, keeping OC's body in the house, talking to him, kissing his forehead once through the blanket as a goodbye).
Illness and terminal illness (Helena is sick and anemic; Rowena is on her deathbed).
Mention of hunting and animal death (boar, frog, mouse, salamander, unicorn).
Blood.

A/N I played around with canon events, having Helena elope for love, and moving the Baron's death before Helena's.
Waldo is the Baron's given name in the Welsh translation, so I went with it. And I named my OC, Helena's lover, John.
I also enhanced the fact that ghosts, in the HP world, can create disturbances in the air and fire… for plot reasons :)

I probably couldn't make this story as original as I would have liked, but this is where my muse went when I read the prompt, so I hope you'll enjoy it anyway :)

Betas: many many thanks to Ikuni, Queenie, Dora and Sky!

"Lady Ravenclaw is gravely ill and requests your presence at Hogwarts," were the words of the messenger. Waldo nodded; he would not refuse anything to one of his former Professors.

Tying his sword sheath to his belt, he made his way back to the stables, from where he had just come after a hunting trip. There was still blood on his clothes, but he did not have time to care. The pull towards the School, even more than Lady Ravenclaw's request, animated him.

He had always loved Hogwarts: days spent bent over parchments, stirring cauldrons, gazing up at the night sky, and peering into the eyes of a certain young Lady, in the hope of catching her looking back at him. There had been so many dreams dancing in her eyes, lighting her up with life and mystery. When she laughed, her hair would bounce with the force of it, catching the light. Her feet were always moving, carrying her from one discovery to another or dancing to some secret tune. When she recounted a story, her hands would gesture animatedly. Once, her hand had accidentally brushed his, and it had taken his breath away. To everyone, she was Rowena Ravenclaw's daughter, but to him, she was Helena, the girl he loved. And she was as luminous as her name indicated, her kindness and beauty bringing light to everyone; and he had always, always found himself inevitably attracted to her, like a moth to a flame—predictably, he got burnt.

Lost in his memories, he saddled his black stallion, who nuzzled him as if to comfort him. Truly, all forms of magical travel were not worth a good steed.

...

When he was at her bedside, Lady Ravenclaw's raspy whisper was no surprise. "Find her."

"There is no trace of her, my Lady," he said. Then, with an effort, the words tasting like ash, he added with pursed lips, "Or her lover."

Helena had eloped with a Muggle farmer, choosing love over duty, choosing another over him—his hand ran to the sword, unbidden.

Lady Ravenclaw's eyes narrowed. "Find my daughter," she repeated. "Bring her home, so that I may see her one last time before leaving this world."

Her bony fingers wrapped around his hand with surprising strength, and as she gripped onto him, he vowed an Unbreakable Vow to bring Helena home at any cost, tying his fate to hers and inevitably signing his death warrant.

…

Leaving Hogwarts, he whispered a directional spell; it pointed south. He rode on. For hours, days, weeks—in vain. Helena, brilliant as she was, must be cloaking from everyone. Still, he urged his horse to go forward, faster, the fire in his veins consuming him and demanding action. The boar crossing his road would do for now to vent his frustration; eagerly, he put his hand to his crossbow.

...

The Unbreakable Vow had an expiration date; Waldo died before finding her, the world turning white around him.

Everything swam out of focus as he was yanked from one plane of existence to another, before being spat back out on Earth. He could feel his stomach churning, but the fall did not hurt. He floated, the lightness of his being making him dizzy without a way to ground himself. Trees, rocks, even his horse—everything was beyond his grasp. He reached for his trusty sword and wand; they were at his belt as they had always been, untouchable by anyone but him. But they were useless now. He huffed, though no air escaped his lungs.

At no point of the Unbreakable Vow had the words "until death" been spoken. He was bound to this Earth and Helena for all eternity—a residual imprint, barely more solid than mist, a ghost. He did not give himself time to dwell on it; now that he instinctively knew where she was hiding, he had a duty to complete.

Casting a last glance at his stallion, who was snorting in distress, he said, "Goodbye, my faithful companion." Not a tear could be shed from his airy eyes, and yet they prickled. "You are free."

Now truly alone since he had embarked on this quest, he let the wind bring him to her.

…

The woman he found was not the one he had been left by. But then, he was not the same man either.

She was in the garden, collecting herbs. Casting a glance in his direction, she emitted a little gasp of surprise, before entering the little shack, turning her back on him, uncaring, but there was nothing he could do about it. He could not take her by the shoulders, force her to turn, bodily throw her on his horse and gallop away. Not even now, as a ghost, could he impress her. The helpless fury he felt contorted the contours of his face, as he followed her right in.

She was picking up a knife. "You always were a good hunter," she said with a shiver, as the temperature in the room seemed to drop in his presence.

There was still something in her of the girl he had loved, something still struggling to live and break free. But her body seemed weakened. While her eyes burned with an insane obsession, she chopped roots with herb-stained fingers and recited incantations with white lips. On her unkempt hair, in which skeletons of dry leaves were caught, she was wearing her mother's diadem, undoubtedly stolen, even if no news had been divulged about it—one more reason for Lady Ravenclaw to want her daughter back.

"I have come to take you home," he said. "Your mother is ill and wants to see you."

She ignored him. Her red-rimmed eyes focused on a human-shaped lump on the bed, surrounded by a magical ward. "Why are you not a ghost, John?"

"Lady Helena," Waldo said, trying to grab her shoulder, forgetting he could not—his hands no stronger than the light spring breeze that had tousled her once shiny hair. "I am here."

"But John is not." Her voice trembled. "The only person who would look past my face… Everyone sought my mother for her intelligence and me for my beauty only, but he—he spoke to me." A tear slid down her cheek.

Gazing avidly at that single drop of water, to be the reason for which he would have once given an ounce of his blood, Waldo reached out only to withdraw his hand when it was mere inches away from her face—that tear was flowing for another man. He gritted his teeth and positioned himself in front of her. He was there, and if she wanted someone to speak with, he could do that.

"Therefore, no. I will not go home until his spirit is restored to his body," she said, finally replying to his first sentences. Then, following his gaze, "The diadem is mine. I need it."

She turned back to her workstation. More ingredients were thrown into the cauldron, dissolving into a fruity smell, before she grabbed a frog from a nearby basket.

"John could not stay," she said. "But I will find another way. The diadem showed me so much knowledge already—" Her voice trailed off as the cauldron bubbled over the fire.

Helena's hands tightened around the frog, which let out a faint croak before being silenced forever.

…

Waldo was confined within these four wooden walls, forced to see Helena succumb further to the allure of Lady Ravenclaw's diadem in an attempt to restore her lover. He knew she had always been thirsty for knowledge, eager to prove herself, but this was different, worse; the way she looked at the diadem when it was not on her head was a mix of terror and greed. She never lost sight of it, with dull eyes that were not dreaming anymore—there was no wonder or fascination in there, just a knowledge too large to comprehend and yet not enough, never enough—as they looked at everything without really seeing it, classifying it either as an obstacle or a resource to her current, self-imposed task. Her gaze was harsh in a way he did not associate with her, and she seemed to disregard any life form.

A daisy, a fly, a frog and a mouse had been sacrificed to her research. So far, she had been able to resurrect only the flower and the fly.

"I gave them to Death, and I took them back," she said. "They are mine."

The occasional travelers in distress she met during her trips were all ignored unless she needed a child's first memory or a widow's tears for her spells and potions.

"A child's first memory is such a labile thing," she reasoned. "They will form another soon. And widows cry anyway."

Perhaps it was fortunate that he was a ghost—she better tolerated his unalive presence—but he could not help but think that had he been alive, they would both be safely at Hogwarts by now. Those frustrated thoughts, he discovered, fueled whirlwinds and flames that he could control.

When she was not collecting ingredients for her potions or creating spells, she just sat beside the bed speaking to John in soft, loving tones. On such occasions, Waldo could not control himself, and his jealousy would call forth strong gusts of wind that shook the small building they were all in—a ghost, a dead man and a desperate woman—making the windows rattle and the door slam repeatedly. Helena did not seem to care. Nothing else mattered but John and the diadem, and her wards kept both very safe.

"The frog and other more complex organisms could not be revived yet, but be patient, John. There is always another way. The diadem will show me," she said, despair and faith warring in her eyes, "like it showed me everything else. Death has killed my joy; I will take away Her power."

But not even Helena could defy Death and win, Waldo thought as his ghostly fingers brushed against her hands, her ashen skin matching his pallor and giving away a decaying soul, trapped in an equally ill body.

Shivering in his proximity, she wrapped her mantle more closely around herself. "Leave me alone," she said, standing up and going near the table that she used as a workstation. "Go back to my mother."

"Give it up, Helena. Return with me to your family, and let your madness fade and be forgotten." He looked towards the bed. "Leave him be. He is dead—"

"Are you not?" she fired back before he could add, "And he is a Muggle." Not much was known about the Muggle afterlife.

With a look of defiance, she put on her mother's diadem before opening her journal and scribbling something down. "He will not be dead for long. And he is still the person I love."

Waldo let his head drop in defeat for a moment; then, looking her in the eyes, his tone harsh, he said, "You will bring back but a shadow—no warmth, no depth, no love."

"Even if it is not real—" She caught herself.

"He is not worth defying Death for," he said.

Her nostrils flared and her voice raised as she reached for her knife. "How dare you?" She banished him from the shack with one hand while cutting a salamander in half with the other.

The next day, she let him back in with a calculating look in her eyes.

…

He used wind to scatter her papers and fire to destroy her ingredients, but her will was too strong, her knowledge too wide to be hindered by a simple ghost, even one whose powers came from his rage, which only increased with time.

He had to stay there because he was oath-bound to her, while she, for her part, had understood that his being a ghost—a point of connection between this world and the next—was beneficial to her research. She was just waiting for the right moment: midnight on a moonless night. That night, by channeling his ghostly energy, she was able to open a portal to the spirit world.

"You are a good hunter," she said. "You can retrieve John's soul."

But the spirit world was too wide, too crowded; he could not find the soul she was looking for in such a brief time. He would not. Upon his refusal, the portal dissipated into nothingness, and they fell to the ground, surrounded by darkness and the smell of incense.

He expected her to cast a Lumos spell, but she did not. He was not bothered by it; his eyes, no longer subjected to physical laws, functioned in the dark as well as in the light. He looked at her; she was holding the diadem rather loosely in her hands, contemplating it, muttering under her breath.

"Will that even work?" she wondered out loud before putting the diadem on. Glancing at him, his slight glow giving his position away, she got to her feet and left the shack, raising wards around the building to make sure he could not follow her.

In the distance, the rumble of thunder carried an unsettling sense of impending doom.

…

The next day, she came back with a unicorn horn and a silver-glowing vial, her eyes sparkling with fever and madness.

"Lady Helena", he said, her name not so much of a greeting as a plea. "What did you do?"

She stuck her chin out, displaying a determination that her voice did not hold. "It is the only way to reunite body and soul when either is lost."

He cursed, knowing her soul was forfeit.

She started working, soaking the unicorn horn in a cup of rainwater and grinding out a stone coming from the riverbed. "Water remembers, you know," she said. "It preserves the memories of those who drank from it just like rain contains the collective memories of us all. I can extort from this little stone the secrets of the Ancients, when the world was young and Gods walked among the mortals. Maybe someone met Death."

He nodded, captivated by her words, despite himself. He had always liked listening to her, and at that moment, he felt like he would do anything for her.

The storm was getting closer. When the first lightning fell, its blinding light flooding the room, she flinched, shaking her head and blinking to adjust her eyes. When she looked down again, she seemed to notice her silver-stained fingers for the first time.

"Ah," she whispered.

She stood up and went in front of the mirror, looking at her reflection as if she saw it for the first time. "I just wanted to feel loved one last time…" She brought her trembling hands up to her face to hide behind them. "But this is not the woman John fell in love with. W-what if he does not recognize me? What if there is nothing left of me—"

She turned towards Waldo, perhaps expecting a denial, an empty platitude that he would not give her. Instead, he said the only thing he could, something she had forgotten, "Helena Ravenclaw was loved by many, not only by John."

After a few seconds, "Is that so?" she asked. "Prove it to me."

In her gaze, dark and terrible, he read the truth. Shook to his very core, he trembled. Despite the physical impossibility of it, his throat felt tight. "That is what you want from me," he said. "You want me to free you."

"I have looked for Death for so long. I did not realize how easy it would be to be found by Her. Not until I kill—" She stopped. "But I want it to be on my terms, while I still feel alive."

The thunder growled, and the floodgates of the sky were opened.

She looked at the silver blood on her hands as she used them to unlock the windows. "May the rain wash away all the blood from both our persons." Her words were barely audible over the noise of the rain falling outside.

"Helena..."

"Do it. Now. While I can still feel remorse… Tonight, this morning, I did not feel it. I was dead inside. Even when I was—It might be too late already, but I want—while I still can—" She headed towards the bed and pressed a kiss on John's forehead through the blanket. "It would not do you any good to be connected to me, beloved, but I will make sure you are cared for, in the next world if not in this." A tear slipped out of the corner of her eye.

That display of love for another man, whether she had planned for it or not, broke through Waldo's final reservations. Called forth by the ghost's jealous fury, the wind rushed into the small shack with a shrill howl, sweeping up Helena's knife. It flew for less than a second before finding its target, its aim true. She fell with a smile, the soft thud of her body drowned out by a crash outside as a tree was struck by lightning. The air carried an odor of smoke, resin, and blood, the last remains of lives lost to fire and iron.

"Helena," he called for the last time, an apology and a prayer turning into a scream of pain.

…

When he looked around next, Helena's ghost was by his side, saying she could not move on, but that she had spoken with John. Bound together from the moment she had asked him for death and he had given it to her, it was easy for Waldo to bring her home now, fulfilling the last wish of a mother's heart. Hogwarts, they discovered more than nine centuries later when another decided to tamper with Life and Death, was exactly where she was supposed to be; and to this day, there they remain.