Disclaimer: HP and his world belongs exclusively to J K Rowling

No Mercy

Credit to Nettie for her suggestions.

Petunia gasped as water splashed across her face, waking her from the stunning spell. "What..?"

Lily smiled. But it wasn't a smile of comfort or of love that sisters normally share; it was a smile of victory. And it was a victory that tasted like chocolate in Lily's mouth; rich and velvety, comforting and tempting, all at the same time. "I was worried you'd never wake up, Pettie." Petunia had hit her head quite hard as the spell had taken effect.

Petunia's head ached and she could feel rough, cold metal around her wrists and ankles, holding her firmly against the damp, mildew covered wall. She tugged at the shackles, testing them for weaknesses. She found none. "Why am I here?"

"That's just like you, Pettie." Lily cupped her sister's face in a mockery of a loving gesture. "Getting straight to the heart of the matter. Most people would have said 'How could you, Lily?' But not you."

Petunia loved her younger sister, but was not stupid enough to trust her as everyone else did. And it was a trust the redheaded and green eyed girl seemed to engender wherever she went. But Petunia knew better. She had once seen Lily in the woods by their home, torturing small animals. Petunia had wanted to step in and beg Lily to show the animals some mercy but unable to do magic herself, she had hesitated when she had seen the look on Lily's face: a look of absolute pleasure, absolute satisfaction, absolute evil. Petunia had instead fled, and never told anyone what she had seen, convinced that they would never have believed her if she had. Now she wished she had at least tried.

"That's because I know you better than most, and I know what you're capable of."

"Then what I'm about to do shouldn't come as a surprise." Lily released her hold, and took out a vial of liquid from her pocket. "You see, Pettie, you have something I want, or should I say someone."

Petunia's heart sank as she realized who Lily meant. "James is my fiancé. You had a chance with him and you blew it."

"All he did was twitter on about you during our date." Lily's face turned ugly. "You knew I wanted him and you stole him from me, Pettie, and now I'm taking him back."

"You can't imagine that he'd ever love you as he does me." Petunia was unable to see how Lily could believe that James would want her, especially as he had already turned Lily down once before.

"Oh yes, he will." Lily waved the vial in front of Petunia's nose. "Do you know what's in here, Pettie?"

Petunia guessed at the contents. "A love potion?"

"Close but not quite right." Lily uncorked the vial. "It's a potion that will make you fall in love with the first person you see after taking it but, deep down, you'll always know that James should've been the one."

"You can't do this." Petunia tugged ineffectually at the chains again. "Let me go, Lily. I promise I won't tell anyone."

"I know you won't." Lily smirked. "You see the potion isn't just a love potion; there's a little something extra in it that will make sure you keep your mouth shut." Lily still had not been entirely honest with Petunia; she had failed to tell her that the potion would also make sure that Petunia's love for James would mutate into hatred over time. "Now James will be receiving a similar potion but the object of his desire will be me."

Petunia was not surprised to hear that Lily had planned this out carefully; not only taking James from her but rendering her unable to tell anyone about what Lily had done. "I take it you have someone in mind for me to replace James."

"Do you recall our new neighbor?" The Evans family had moved to Guildford in Surrey from Grimsby a few months previously.

Petunia shuddered. "You mean Vernon Dursley?"

"Good guess. I've seen how he looks at you, Pettie." Lily sniffed the vial of pure yellow liquid as she spoke, faint whiffs of honeysuckle and vanilla floating out of the vial and tickling her nose. "This potion will make you look back at him in exactly the same way."

"No." Petunia shook her head frantically. Vernon Dursley made her skin crawl. Even though he was only around nineteen or twenty, he was already massively overweight, and showed signs of getting bigger. Petunia had once seen him in town at a fish and chip shop, eating as though he was starving, the food being crammed relentlessly into his oversized maw. The memory of it made Petunia want to vomit.

"I'm afraid so." Lily re-corked the vial before she gave into its tempting smells and drank it herself. "But before I take James and give you to Dursley, I'm going to take something else from you."

Now Petunia saw the sadistic look on her sister's face; the same look she had once worn as she had torn a baby squirrel apart. "What do you want?" Petunia's voice shook with fear.

"Your potential to do magic," Lily whispered, her voice full of joy and anticipation. "You see, it's not enough that I'm the brightest witch of our age. I also want to be the most powerful witch ever. And I know that as a squib, while you can't do magic as I can, there's still that potential inside of you; a very concentrated potential that you could pass on to your children, a potential I'm going to steal. You see, your potential is going to make my magic just a little bit more powerful."

Petunia challenged Lily's ability to steal such a thing from her, even though she had no idea of whether Lily was that magically advanced. "You're not capable of that kind of magic."

A dark, silky voice came out of the shadows just beyond where Lily was standing. "But I am."

Petunia's blood ran cold as the voice's owner stepped into the light, and even though she had never seen him before, Petunia instantly knew who it was who now faced her. "You!"

Voldemort placed a hand on Lily's shoulder. "Yes, me. If I had my way, I would've just killed you but I can never say no to my most faithful. And Lily is exactly that, one of my most faithful." He turned to Lily. "Are you ready?"

Lily nodded eagerly. "I am, my Lord."

"Then kneel." Voldemort pulled out a stone and placed it in Lily's hands, keeping one of his own hands on top of it.

Petunia began to cry with fear, not really knowing what to expect. "Please no, please. You can't do this to me. Have mercy. Have mercy for pity's sake."

Voldemort ignored Petunia's appeal, and aimed his wand at her. "Rapio Magus Facultus Petunia Anne Evans."

Petunia screamed with pain as her body became taut, and she arched upwards, straining against the chains, her eyes bulging as her potential magic was forcibly ripped from her body. She knew the moment the last drop of it had been drained from her as she became like a limp doll, only the chains' grasp preventing her from falling to the ground.

The stone in Lily's hands now glowed with a silvery light, and, keeping his hand on the stone, Voldemort turned his wand on Lily. "Donum Magus Verus Lily Claire Evans."

Just as Petunia had, Lily arched up as the magical elixir taken from her sister filled her body. Only she did not scream out in pain. Instead she screamed out in ecstasy; her face was almost orgasmic as the stolen potential magic mingled with her own magic, and she became more powerful.

As the spell ended, Voldemort took back the stone, and helped Lily to her feet. "I believe you can handle things from here, Lily."

"I can, my Lord." Lily took Voldemort's hand and kissed it. "I give thanks to you."

"Return when the deed is done." Voldemort withdrew his hand, and faded back into the shadows. "We have things to discuss."

Sagging in the chains, Petunia was still crying, a feeling of weakness and despair having invaded her limbs. Lily released the chains and Petunia fell to the ground, Lily standing over her. "It's time to go, Pettie."

Petunia was powerless to resist Lily as she took her arm and apparated them both to their home. "But you aren't supposed to be able to do magic in the house."

"No tracking charms on my wand," Lily informed Petunia. "It makes it easier to do this." Lily then aimed her wand at Petunia, and cast a curse that was banned in civilized wizarding society. "Imperio."

Petunia was unable to fight the strength behind the command, and against her will found herself choosing clothing from her wardrobe. It was clothing meant to entice, to titillate, to encourage, and Lily had her wearing the clothes in a way that Petunia never would have: buttons left open, a black lacy bra under a sheer white blouse, and a hemline hiked up far higher than Petunia deemed decent in polite society.

Lily smirked at the disgusted look on her sister's face, and made another demand of her. "Take off James' ring, Pettie."

Petunia fought hard not to obey but in the end she slid off the ring, a tear tracing its way down her cheek as she placed the ring on the dressing table in her bedroom. Only then did Lily apparate them both out of the bedroom.

Through the misty fog that surrounded her mind, Petunia became aware that they were standing outside of a bowling alley; a bowling alley she knew Vernon and his cronies hung out at on a Friday night. Her mind screamed at her to fight but Lily's will was too strong, and Petunia meekly followed her sister inside when ordered to do so.

Inside, Vernon Dursley was about to take his turn when Dave, his best mate, nudged him. "What is it?"

Dave grinned and gestured behind him. "Isn't she that bird you fancy?"

Vernon almost dropped his bowling ball at the sight of Petunia's outfit. "Bloody hell!"

Dave nudged him. "Are you going over there then? I know you want to do her."

"Nah." Vernon turned his back on the sight of Petunia, and took aim at the skittles at the end of the bowling lane. "She's out of my league." All of his friends sniggered as Vernon's ball went astray and dropped into the gutter far short of his target, his concentration blown to smithereens by the sight of the scantily clad Petunia. "Shit."

"Just go over there," Dave urged. "You don't know if you don't try."

"She's engaged, Dave." Vernon had seen the emerald ring that sat on Petunia's left hand; a large ring that he knew he would never be able to afford in a million years.

"I don't see a ring on her finger," Dave noted as the two girls headed past them, Dave flashing Lily a smile she ignored.

Vernon ignored his friend, and picked up his second ball to take his next shot, trying not to look at Petunia. It was a battle he was going to lose.

Several tables away, Lily sat Petunia down and handed her a glass of vivid green limeade. "You're going to keep your eyes on Dursley, and drink this… all of it."

Still under the Imperius Curse, Petunia did as she was ordered. As the potion hidden inside the innocuous liquid took hold, Petunia shared a small smile with Vernon, who had given up trying not to look at the girl of his dreams, and he smiled back.

Lily whispered to her sister, "Go over. Ask him to show you how it's done."

Petunia got to her feet and headed towards Vernon, and Lily watched in satisfaction as the large youth wrapped his arms around Petunia and began to demonstrate how to bowl.

James Potter could barely believe what he was hearing. "But, Nia, darling, I love you."

"I'm sorry, James." Petunia could not help the words that flowed unbidden from her lips. "I don't feel the same way. I've met someone else."

After pleading with Petunia and getting nowhere, a defeated James took back his ring and vanished, leaving a heartbroken Petunia behind.

As the last term of school progressed, Lily made the most of James' despondency. She listened to James' ranting about her sister's lack of love; she sympathized with him; she offered him comfort. She also slowly fed him a potion in his drinks that would make him see her in a different light.

Petunia's heart therefore broke again when, on returning home from Hogwarts at the end of her seventh year, Lily announced that she was engaged to James. It was the straw that broke the camel's back, and Petunia moved out of her parents' home, unable to stay under the same roof as Lily. She also refused, despite her parents' pleading with her, to attend James and Lily's wedding, not wanting to see James look at Lily as he had once looked at her.

On the day of the wedding, Petunia cursed her sister, and she continued to fight against the potion that Lily had fed her but she had no defenses against its effects. And two days after the wedding, the potion worked with Petunia's depression, making Vernon seem all the more enticing, and Petunia slept with him. But every fiber of her being had screamed out in disgust as his gargantuan body had covered her slight one. Her only sliver of comfort had been the memory of her first time with James, and it was a memory she thought she would treasure forever. But she was wrong.

As time went by, the potion's effects began to mutate and strengthen, as Lily had known they would, and Petunia's love for James began to change to hate. And as she began to hate James, she also began to hate magic for what it had done to her. Petunia therefore vowed on the day that she found out she was pregnant with her son, that she would never let him anywhere near a world that had stolen the man she had once loved, and the sister she had once adored and promised her parents she would protect.

Moreover, Petunia's hatred for magic now ran so deep that when she was informed that her parents had died in a car crash six weeks before her son's birth, she refused to attend their funerals, unable to face Lily and James. Her visit to her parents' graves had therefore only taken place after the service had finished and everyone had left.

With no-one to hear her, Petunia had opened up about Lily and told the truth, even though it was too late for her parents to do anything about the situation. And Petunia had cried hot, bitter tears as she cradled her stomach, and told her mother and father that she would miss them, and that she would try to make them proud.

As her tears abated, Petunia stood up. "Mum, Dad, I'm so sorry I let you down. I said I'd take care of Lily but I failed, and that world swallowed her up and turned her into someone I no longer recognize. I'm so sorry."

Petunia then walked away.

When their son was born, Vernon named him Dudley, which was his best friend Dave's real first name. And Petunia gave him the middle name 'Jacob' which was a variant of the name James. Even as she had told herself that she hated James Potter, she had found herself in the local bookstore looking up the meaning of his name, and she had seen that Jacob was a variant of it.

Right up until the last moment when the Registrar had asked for Dudley's full name, Petunia had intended to give Dudley the middle name 'Stanley' after her father. But the name 'Jacob' had come out of her mouth instead. Deep down Petunia knew why she had done it. Despite the potency of the potion, her love for James had been strong, and a tiny glimmer of it still remained in her heart; hidden away from the potions' effects.

But this glimmer was about to fade when, a mere five weeks after giving birth to Dudley, Petunia received an envelope in the mail. Opening it, she discovered a printed card announcing that James and Lily Potter were now the proud parents of Harry James Potter, who had been born on 31 July 1980 and had weighed 7lbs 6oz.

The card had fluttered to the ground as Petunia had turned the envelope over in her hand, and she recognized the postal district of Godric's Hollow; she also recognized Lily's handwriting, something she knew she should have done before she had opened the envelope. "Why can't she just leave me alone?"

Angry, Petunia burnt both the card and the envelope, and she then went to see to her beloved son, trying not to think of Lily and the life that should have been Petunia's. It would be more than a year later before Petunia would have reason to think about her sister again.

After killing James, Voldemort made his way upstairs in the cottage, finding Lily in the nursery. "Lily, come away."

"You said you wouldn't hurt him. You said you would leave us alone."

Lily had learnt of a prophecy from Albus Dumbledore, her former headmaster, that spoke of a child born on the last day of July who could defeat her master. Ever loyal, Lily had told Voldemort about it, never once imagining that it would be her son in the firing line as Harry had not been due until the middle of August. She had always believed that it would be Alice and Frank Longbottom's child instead.

Even when Harry had been born early, Lily had been convinced that it would still be Neville Longbottom who would become Voldemort's victim. However, after careful consideration, Voldemort had decided that, after Lily had revealed that Harry had shown signs of accidental magic at just over one year of age, Harry was the chosen one of the prophecy. "You promised."

"I didn't know." Voldemort too had believed that it would be the pureblooded Longbottom child who would be the threat; not the half-blooded infant that Lily had borne. "Lily, I have to do this. Move out of the way."

As Voldemort advanced on her son, Lily moved to stand in front of the crib, her body shielding Harry, and despite Voldemort's demand, she stood her ground, her words bubbling out in a frenzied plea. "Not Harry, not Harry, please not Harry!"

Voldemort had no wish to harm one of his most faithful, and he again implored Lily to just let him do what he had to. "Stand aside you silly girl … stand aside now."

Lily glanced behind her at the child she had not expected to love as she did, and she continued to plead, offering Voldemort an alternative to killing her son. "Not Harry, please no, take me, kill me instead."

Voldemort sighed, his face set and he withdrew his wand.

Lily knew then that Voldemort was going to take her son's life, and she continued to stand between Voldemort and her son, refusing to move aside. "Not Harry! Please… have mercy… have mercy… "

As Lily defied Voldemort for the third and final time, Voldemort aimed his wand and got ready to utter the curse that would signal his own doom, even though he did not yet know it. To Voldemort, at that moment, Lily was just an obstacle and not the beginning of his downfall, and he subsequently dealt with her; regret about Lily's wasted talent his only emotion as he killed the redheaded woman.

"Avada Kedavra."

As Lily fell lifeless to the ground, Voldemort turned his wand on the crying baby, and took aim. "Avada Kedavra."

A flash of light, pain, so much pain, and a ripping sensation, and Voldemort was separated from his body, and baby Harry was left screaming in his crib, blood pouring from a strange shaped cut on his forehead.

Afterwards Albus Dumbledore said that it was blood magic that had saved baby Harry from the same fate that everyone else had suffered at Voldemort's hand. And he also said that he believed that Lily had been only been able to invoke the old, almost forgotten, blood magic because she had loved her son beyond reason, that she must have offered herself in Harry's place, and because she had been so powerful. He had at least been right about Lily's power.

But Albus had had no idea that Lily had only been so powerful because she had not only stolen her sister's potential magic, which should have filtered down to Dudley, but she had taken other people's magic as well. And each time she had done so, just like Voldemort, Lily had never showed any mercy to her victims.

And this lack of kindness was about to rebound on Lily's own offspring, as Albus decided that Harry would have to be taken care of by Petunia, so that the blood magic would not be wasted. He had therefore left Harry on Petunia's doorstep for her to find together with a letter explaining what had happened and why Harry needed Petunia to care for him.

The morning after Albus had done so, Petunia had been horrified to find baby Harry lying at the entrance to her house, a letter tucked into the blankets that swaddled him. Petunia knew without opening the letter whom the baby belonged to, and she did not want him nor what he represented. But after reading the letter, Petunia thought about how she would feel if it had been her son who had been orphaned, and she had reluctantly taken Harry in for James' sake and what they had once shared.

Over the next few weeks, Petunia tried her very best to be kind to her sister's only son. But it was hard, so very hard, as every time that Petunia looked into baby Harry's eyes, it was never his eyes she saw, it was Lily's. She still tried though. However, Petunia's efforts ended the first time Harry displayed a sign of magic, and her hatred of all things magical had Petunia vowing to quash it out of him, no matter what it took.

And, in fulfilling her vow, just as her sister and Voldemort had shown her no mercy when taking her potential magic, Petunia too would show none to Harry in trying to curb his.

Fin