The first time Cersei saw the Tyrell girl it was late afternoon; light trickled into Baelor's Sept in thin, lazy tendrils. One of the last, most beautiful summer days, she would later recall.

She was a lovely child, Cersei noted offhand. Smooth white skin, perfectly coifed hair. She dressed like someone of consequence; the cut of her velvet gown bespoke the latest fashion. Still too young to be more than pretty, she mused, but she could be a temptress in a few years. The queen grinned at her own reflection in the windowpane; the beauty of some nameless court girl hardly bothered her.

As she watched, an attendant gestured in Cersei's direction and the girl turned to smile at her. Cersei sighed; she'd hoped to get through the afternoon without too much sickly-sweet conversation. She smiled back; one should always be gracious, especially in times like these. Threading her way through the pews, she laid her hand on the girl's shoulder.

"Are you new at court, my dear? I don't believe I've seen you about before."

The girl blushed prettily. "Yes, your grace, I arrived last night with my lord father."

She was part the Highgarden retinue then, Cersei thought. Interesting.

"He spoke of the grandeur of the capital, but the majesty of it cannot be captured with mere words!" she continued, her eyes widening noticeably.

Cersei smiled back. There was always room for another simpering girl at court. "I am moved that you think it so, my dear. Perhaps you would honor me with your name?"

The child blushed again. "Oh, a thousand pardons, your grace! I am Margaery Tyrell." She curtsied, her head tilted modestly at the floor.

Cersei smiled again, and clasped the girl's hand between her own. "Welcome to King's Landing, Lady Margaery. I hope that the city continues to delight you, and that you enjoy your stay with us."

The girl gave another vapid smile. "I'm most certain I will, your grace."

It wasn't long before Margaery began to attract Cersei's attention again. She associated with every group of noblewomen, ingratiating herself with a fluid ease that it had taken Cersei years to master. Everyone who knew her counted her as a friend, and as of yet Cersei had found none who claimed her as an enemy.

"You are truly a Highgarden flower," she told Margaery one day as they walked back from prayers together. "Only here a short time, and you're already blossoming."

Margaery blushed and looked down at the floor. "Your grace is too kind. Any flower would blossom after being planted in such rich soil. And it is the garden's ruler, she who looks after the flowers," Margaery said, glancing at Cersei, "who truly makes the flowers grow."

Clever, Cersei thought. She was surprised. Surprised and pleased. The court was stifling in its stupidity and arrogance at times; it would be refreshing to talk to someone as humble and bright as Margaery seemed to be. To have her as a daughter-in-law and a political ally would be even better.

Her thoughts shifted to the disgraced Stark girl. Sansa was remarkably similar to Margaery, albeit in all the wrong ways. Pretty and charming, certainly, but thoughtless like no other. Cersei frowned. With the Starks disgraced, [repetitive] there was little enough reason for Joffrey to marry Sansa save for how pretty he thought her. She looked back at Margaery, calculated how Joffrey would react to her ivory skin and soft auburn curls.

"Dear, would you perchance grace me with your presence on the morrow? I have a lovely selection of pastries," she asked.

Margaery smiled, lovely as always. "Your Grace, I would be honored."

"You've certainly endeared yourself to the commoners," Cersei remarked one day as she and Margaery sat down with their embroidery after supper. The latest reports had detailed how Margaery had gone to the ramshackle streets of Fleabottom with a minimal guard and personally handed out bread to the children. This was the most recent incident in a string of charitable works. They'd amused Cersei at first; she'd dismissed them as thoughtless whims of fancy. But as the girl grew more ambitious in her charities, and more and more cries of "Long live Lady Margaery," reached Cersei's ears, her amusement was fading.

Margaery laughed lightly. "They are so kind to me, I cannot help but show them my affection in return. And as I am to be their queen one day, it seems fitting that I should learn to care for them, don't you think?"

A shiver ran down Cersei's spine. "I understand, my dear," she murmured, keeping her voice even and warm. She leaned forward and gently pushed a curl away from the girl's face. "Very commendable. But you'll have plenty of time to learn how to be a proper queen; you mustn't try your delicate constitution by attempting too much too quickly."

Margaery nodded and lowered her eyes demurely. "Yes, your grace. I simply hope that I will to one day be able to aid my king as admirably as you have."

It was a clever statement, Cersei observed coolly, flattering and understated in the same stroke. Combined with the girl's youth and charm, Cersei could see how Margaery would be able to fool almost anyone into thinking she possessed no untoward ambition and was simply a charming, gracious child.

But Cersei had been such a child once, and she remembered how easy it had been to hide true intentions behind delicate lashes and pretty smiles. Unfortunately for Margaery, Cersei thought, she was facing the one woman in all of King's Landing who could see through her innocent façade with a passing glance. And what Cersei saw was a yearning for power, the need for a throne to sit on.

She kept this to herself, of course, and chatted animatedly with Margaery about court gossip instead. When the daylight faded and Margaery regretfully laid down her needle, Cersei bid her good night with a gentle kiss on the forehead.

She sat alone long into the night, long after her candles melted into puddles of wax, thinking feverishly of what she needed to do to destroy Margaery Tyrell.

The day she was to visit Margaery's cell, Cersei donned a red satin gown edged with Myrish lace and set a golden circlet on her brow with a satisfied smirk. She walked along the halls of Baelor's Sept with six maidservants, six guards, and a smile on her face.

Her smile widened as she entered the antechamber of the prison, despite the unpleasant smell. There was something decidedly delicious about seeing a rival brought so low.

Margaery's face was twisted into a snarl; her beauty distorted hate, like a reflection in broken glass. With her teeth bared and her neck clenched, for a single disconcerting instant the girl reminded Cersei of a lion. "You won't get away with this, you vile woman!"

Cersei stood patiently as the girl cursed her. Only when Margaery slumped down onto the floor and began to cry did Cersei lean in. "You tried to take my power, dear," she whispered. "Tried and failed. And for that, I will end you."

The girl's muffled sobs followed her as she strode out of the cell and down the corridor. Cersei smiled, feeling more secure than she had in weeks.

It was the stranger's own luck that their positions were reversed at their next meeting, Cersei thought dully. Same prison, same ugly bars. Only this time, Margaery was free to go and it was Cersei who was trapped with no way out.

Her hair was a tangled mess but she didn't care, didn't care at all. Her nails were broken from scratching at the door and her throat was raw from screaming. But the guards at the cell door were mute or simply uncaring, and she found herself still alone, still imprisoned, as night fell.

The door to the cellblock opened soundlessly. Two men in hateful green and gold livery entered first, holding tapers. In the weak, guttering candle light, Cersei watched Margaery step through the doorway. Skin still pale like alabaster, but for the first time Cersei saw the darkness dwelling on the planes of skin the candlelight didn't reach. Deep shadows, dark shadows, and suddenly Margaery seemed like much more than a mere child playing at being queen in summer silks and velvets.

"Cersei Lannister," she said.

"Your Queen," Cersei reminded her. She remembered the last time they had spoken freely, recalled the curses that Margaery had thrown at her. She straightened her back and stared into the girl's eyes. She was a queen yet.

Margaery continued as if she hadn't heard. "Cersei. We stood thus several days past, and you called me a child."

And suddenly, staring into Margaery's flinty eyes, Cersei felt her mouth dry. "You're yet a child," she whispered.

Margaery tilted her head, the motion calm and slow. "Perhaps. But not for long." She stepped forward until she stood flush against the bars. Cersei smelled roses faintly in the chill air. "You said, Cersei Lannister, that you would end me. That I had failed." She paused and narrowed her eyes. "But hear me now."

"You will die soon, reviled and abhorred from Dorne to the Wall. Your name will be a curse in the crudest taverns of Volantis, your likeness spat upon even in distant Qarth."

"You said you would end me. But hear me now, murderess, adulteress, speaker of false oaths, dealer of sweet poisons."

"Your grandchildren will never know your face, and their children will never learn your name. Every portrait, every statue, every likeness of you, no matter how simple or small, will be smashed or burned until nothing but dust and ash remains. Every mention of you in every book in The Citadel will be inked out. This I swear, Cersei Lannister."

Margaery smiled slightly, and Cersei shivered. "You said you would end me. But I will erase you. When I am done there will be nothing left of you, nothing, not even a whisper of your name on the wind."

With that, she turned and walked smoothly from the room. As her attendants followed, Cersei felt a wordless cry tear itself from her lips. Cersei Lannister, who had never begged for anything in her life, fell to her knees and stretched a hand, pleading, through the bars.

Margaery looked back over her shoulder and for a split second, a moment suspended like the last grain of sand in the middle of an hourglass, their eyes connected.

Then Cersei looked away, and the door slammed shut.