This is a gift for brownsugarbouquet as a part of antigone2/idesofnovember's 2019 Usamamo fanwork exchange. She wanted fluff or light angst, and preferred something set in the SilMil. Some additional research (e.g. combing through her blog) told me she likes feelings and pretty things (same tbh), so I tried to work that in here as well :). I hope I was able to give you something you enjoy! A thousand thanks to Kasienda, who literally has a million more important things going on right now (like for real) and still took the time to beta this and helped me turn a crap draft I wasn't super happy with into something I feel good about.

Thanks also to FloraOne, MoonlightUsa, UglyGreenJacket, and QueenRisa, all who took the time to listen to me think aloud (read: whine) about my writing.

Finally, thanks to antigone2 for organizing this whole thing. It was my first time doing anything like this, and I had so much fun!

Domino

Prince Endymion stretched his arms out over his head, leaned back, and closed his eyes as his body came to rest on the beach's warm, powdery sand.

Opportunities for him to slip away from royal engagements were few and far between. This late afternoon, he'd seized the few hours of free time he had and gone for a swim. Inhaling the salty sea air, Endymion basked in the sun's heat, the sound of crashing ocean waves and squawking seagulls in the distance like a lullaby to his soul.

Suddenly, a loud pop and a blinding flash of light cut through the idyllic afternoon.

Endymion shot up, opened his eyes, and scanned the horizon. He squinted at the faint outline of something, rather, someone, right at the shore's edge before grabbing the sword that lay at his side and cautiously approaching.

It was a woman. At least, he thought she was a woman, but she was unlike any other woman he had seen. Her pale skin nearly glowed in the sun's light, and she wore a white silk dress that billowed around her in the gentle breeze.

And her hair. Two seemingly endless streamers of golden hair, flowing from two neat buns atop her head.

Endymion swallowed, his tongue stuck to the roof of his mouth.

She stood at the water's edge, two delicate hands excitedly clasped over her mouth as she took in the beach's sights. Her blue eyes shone with delight as they darted from the sand to the sky to the waves ahead her.

Having noticed Endymion, she turned her head and paid no attention to his raised sword. "Isn't this the most amazing thing you've ever seen?" she asked breathlessly, enthusiasm bursting from every word.

She used the Common Tongue, and Endymion couldn't place her unique lilt. Then, he noticed the symbol on her forehead: a golden crescent moon. Endymion sucked in his breath and slowly lowered his sword.

"Are you…," he began, "A moon being?"

The woman stiffened and whirled to fully face Endymion with narrowed eyes.

"Moon being? Is that what Terrans are taught to call Lunarians?" she hissed, glaring at him.

Endymion was taken aback. No one had ever spoken to him with such scathing disdain before. And while he knew the proper thing to do was apologize, he was entranced by the flush in her cheeks, the flare of her nostrils.

He crossed his arms over his chest and grinned cockily at her.

"And are Lunarians not taught that contact with Earth is forbidden? Or did you just not pay attention in your childhood lessons?"

The woman's eyes widened as she marched closer to Endymion, fists clenched, looking like she was ready to spit fire. "Why you arrogant…eep!" The woman started as cold ocean water swirled around her feet, soaking the hem of her dress. She scuttled backward, trying to avoid the tide that had begun to roll in. In the process, she stumbled over her skirts and fell flat onto the sand.

Endymion burst into laughter even as he moved to help her. "It's just the incoming tide." He quirked an eyebrow. "Your home's doing, I believe."

She scowled at his outstretched arm, gave a little humph and crossed her own arms over her chest.

Endymion cleared his throat to suppress another wave of laughter, still holding out his arm. "Forgive me, my lady. Shall we start over?"

Reluctantly, she took his hand and allowed herself to be pulled up.

"My name is Endymion."

A spark of recognition flashed in the woman's eyes.

"Serenity."

They had both known, of course, the instant they revealed their names, whom the other was.

While contact between the citizens of the Earth and the Moon was forbidden, it was the Moon Kingdom's responsibility to guide, protect, and watch over the Golden Kingdom. To that end, the reigning monarchs of the two kingdoms met once a year. No one else was permitted to attend, and the conversations between the two were a tightly kept secret.

Serenity and Endymion had both grown up knowing this would one day be their responsibility. They were forbidden to meet before then, and the eventual relationship between the two was to be kept strictly political, the Lunar monarch providing counsel to the Terran one.

The minute they'd realized each other's identities, they should have cut off contact. They could have pretended their initial encounter never happened, and never spoken of it again.

But Endymion couldn't help it.

He found himself addicted to Serenity's fascination with everything she saw. He wanted to show her everything, anything to elicit that curious smile that lit up her face and the subsequent fluttering feeling in the pit of his stomach.

They'd waded into a tidal pool and he'd shown her starfish and sea urchins and minnows. She'd wrinkled her nose adorably when her foot got caught in a tangle of seaweed. He'd led her into the ocean and taught her how to jump over the crashing waves, both weighed down by their clothes.

Over the next few months, Serenity kept visiting Earth, and Endymion presented her with everything his planet had to offer. The capital city of Elysion's magic allowed sandy beaches to coexist with snow-capped mountains, lush forests to stand proudly alongside flower-dotted meadows, and Serenity drank it all in, her eyes wide with amazement.

Endymion never felt more connected to his kingdom than when he was out enjoying its nature. He could feel the power of the golden crystal pulsating in his veins with each brush of wind, each wave's crash, each drop of snow.

And it all intensified when he saw his planet through Serenity's wonder-filled expression.

If Endymion was honest with himself, he had been smitten from the first moment she'd narrowed her fathomless eyes at him.

He found himself falling for her more as he took in her awe at rocky, red-tinged canyons, her delight at turtles lounging on moss-covered rocks, her fascination with rushing waterfalls and butterflies that floated lazily by.

At first, it seemed she was just curious about the Earth and all the senses its environment stimulated. But then, one sticky summer evening, the two sat on the edge of a mountain, watching fireworks from a festival go off in the distance, when Serenity tentatively reached for Endymion's hand and clasped it in hers.

Romance between the two was forbidden. Any interaction at all was forbidden. But, in that moment, he couldn't resist.

He leaned in closer, his heart beating a frantic rhythm in his chest as Serenity mirrored his movements. And when her trembling lips met his, he drowned in her scent, her taste, her touch.

The first few times Endymion visited Serenity on the Moon, he'd been overcome with vertigo and she'd giggled at him as he struggled to maintain his balance.

He had since grown accustomed to the Moon's lack of gravity, and now equated the pleasant lightheadedness he felt there with being around the kingdom's intoxicating princess.

He furtively darted between the Moon Palace's marble columns, his cape swishing behind him in the darkness.

They both knew they were playing a dangerous game.

Anti-Lunarian sentiment had been growing on Earth, whipped up by a rebel named Beryl in the North. The rebels accused the Lunarians of being an elitist, power-hungry people intent on controlling the Golden Kingdom. Terran forces were doing all they could to prevent an uprising.

The knowledge that the heir to the Terran throne had begun an amorous affair with the Moon Princess would no doubt stoke the flames of rebellion.

Lunarians took pride in their ancient role as guardians of Earth, devoted to watching over and protecting the Golden Kingdom from a distance. A relationship between their princess and the Terran prince would fly in the face of time-honored tradition.

But they couldn't help themselves.

Endymion was cautious, as always, as he quietly slipped into Serenity's chambers, closing the heavy wooden door behind him.

Her balcony doors were open, the chiffon curtains unmoving in the Moon's still atmosphere. Endymion smiled to himself upon noticing Serenity's shadow on the balcony's stone floor—those distinctive pigtails—and made his way outside.

He immediately realized something was amiss; the presence he felt was an unfamiliar one. Endymion drew his sword and approached the figure leaning against a pillar in the shadows.

"Who are you? Who dares impersonate the Crown Princess of the Moon Kingdom? Where is Serenity?"

The figure moved away from the pillar, and Endymion gasped as she came into the light. The hairstyle was the same, but it fell to the floor in silver waves. She was taller than Serenity, and her eyes were light gray rather than the deep blue Endymion had grown so accustomed to getting lost in. He still towered over her, but the commanding presence she exuded was unmistakable.

He instantly knew that he stood before the most powerful person in the universe.

His forbidden lover's mother.

Endymion dropped his sword and fell to his knees, bowing his head before the monarch.

"Your Majesty," he murmured. His tone was reverent, but the trembling cadence in his voice betrayed his fear. Queen Serenity would be justified in having him arrested and executed for treason. "Forgive me."

Queen Serenity's eyes narrowed, and Endymion was reminded of the first time he'd met Serenity, all those months ago on the beach.

"Forgive you, Prince Endymion?"

Endymion winced.

"Forgive you for breaking a sacred law? Forgive you for sneaking into my daughter's room under the cover of night?" The Queen's voice was quiet, but there was an edge to her questioning. Steely. Powerful. Unyielding.

"I'm surprised by you, Endymion. Your father speaks highly of you, that you are sensible, honest, loyal to your people. And yet, I find you here, willing to risk war between our kingdoms for a pretty face."

Endymion's head shot up. "No!" he cried, more loudly than intended, appalled at the Queen's implication.

He fixed his eyes on her, his gaze unwavering. If he were to be executed, it would be for the truth. He wouldn't allow what he and Serenity shared to be cheapened into some tawdry affair.

"Your Majesty, if you believe I see Princess Serenity as nothing more than a pretty face, a silly romantic tryst, you are mistaken," he bit out sharply. He took a deep breath, trying to calm himself. "Your daughter…" his throat tightened with emotion, "...she's light in darkness, compassion in the face of selfishness. She inspires me to be better than I ever thought I could be. She's...everything to me."

With the rustling of fabric, Queen Serenity knelt in front of Endymion and gently placed a finger under his chin, a smile playing at the corner of her lips. "My daughter is precious to me, Endymion. I had to be certain she is to you as well. Now, let's talk." She gestured for him to stand.

Endymion's heart still pounded furiously as he followed Queen Serenity to the balcony's edge.

He glanced at his blue planet, hanging in the starry sky in front of them, a conspicuous reminder that he was not supposed to be here, that they were not supposed to be having this conversation.

"Your Majesty, I never intended for things to go this far. I'm aware that I've broken the laws of both of our kingdoms, that I've betrayed my responsibilities. It's just…" he trailed off. "Serenity."

"Has Serenity ever told you about her father?"

"No," he replied, surprised by the question.

Since Serenity's first appearance on the beach, Endymion had studied everything he could about the Moon Kingdom. It was a highly matriarchal society, thus, little was ever written about the prince consorts. He had learned that Serenity's father died shortly after she was born, but no one seemed to think it was important to write much else about him.

"He was a good man, a kind man," Queen Serenity stared into the inky sky before them. "But," She bit her lip almost imperceptibly. "I was never in love with him."

Endymion stood frozen, unsure of how to react to the monarch's confession.

"As a young girl, I didn't want this life. I resented the obligation it thrust upon me. I loathed the deference people showed me, the loneliness I felt from always having to put on an act and never making any genuine friendships."

Endymion inhaled sharply. In all he had heard and read about Queen Serenity, she was someone who was deeply devoted to her role, an exemplar of a monarch who always put her kingdom above all else.

"I often snuck out of the palace, disguised as a common woman. One night, I met a man." Queen Serenity's gaze grew wistful. "He had my heart, and I his." She glanced at Endymion. "Something it seems you and my daughter can relate to, young prince."

Endymion's cheeks grew warm and he nodded.

"It wasn't to be. My parents forbid me to wed a commoner, and instead arranged a marriage with a Lunarian noble. I know many arranged marriages work well, your parents' as a prime example."

"And our marriage did work well, in all ways but one. I loved another. Maginus also loved another. And we took solace in each other's company, all the while knowing we could never completely share our hearts with each other, as they'd both been stolen long ago."

Endymion was stunned. He'd grown up around whispers of how the Lunar monarch was an untouchable, all-powerful deity. He had never considered her humanity, and the vulnerability she showed him now left him reeling.

"When Serenity was born, we swore we would never arrange a betrothal for her. Perhaps it was our youthful naivety. I've matured since then, and I understand the sacrifices a monarch must make for her kingdom. But that's the one thing I've never been able to let go of. I want nothing more than Serenity's happiness."

Queen Serenity gave Endymion a sidelong glance and smiled wryly. "Of course, I never expected her to find happiness with the one person in the universe most forbidden to her."

A sudden feeling of dread shot straight to Endymion's core. This was the part where Queen Serenity was going to say she understood, but that it was still impossible. Panic rose up in him at the idea of being explicitly forbidden from seeing Serenity, and at the knowledge that he would anyway, despite risking both of their lives and kingdoms in the process. The blood rushed in his ears. It was hard to breathe.

Endymion tried to steady himself, clammy palms gripping the smooth marble balcony railing.

"H-how did you find out?"

Queen Serenity's expression hardened, her tone commanding once more. "Endymion, it is my business to know of any happenings in my kingdom that may threaten peace." Her gaze softened. "And, my dear, you two are not nearly as discreet as you think you are."

"I'm sorry."

Queen Serenity raised an eyebrow. "Are you?"

Endymion turned to face the Queen fully, his chin raised, gaze confident, every bit the prince he was.

"I am sorry for threatening the peace. I am aware of the current threats to my kingdom. I know the rebels thrive on stirring up anti-Lunarian sentiment. I know my relationship with Serenity is the potential spark that could light the powder keg and start a war." He took a deep breath. "But, your majesty, I am not sorry for being in love with your daughter."

"I know."

To Endymion's surprise, Queen Serenity was smiling at him.

"As I said, I want nothing more than my daughter's happiness," she said softly. "I've been watching the two of you, and it's clear you make her happy."

"I know it's radical, but…" she pursed her lips. "My annual meeting with your father is quickly approaching, and one of my goals is to discuss how to manage the unrest in your kingdom. Perhaps an alliance between the Earth and Moon is precisely what is needed."

Endymion's eyes widened. "An alliance?" He sucked in his breath, barely daring to hope. "You don't mean?"

"I do, Endymion. Perhaps a marriage between you and Serenity is just what is needed to show your people that we are not the untouchable elitists so many of them think we are. We could usher in a new era of collaboration between our kingdoms, make our relationship a more equal partnership."

Marriage to Serenity? With the Queen's blessing? Endymion's heart raced, and he couldn't stop the boyish grin that spread across his face.

"Thank you, your Majesty." His voice was thick. "I never imagined-"

"Nor did I," the Queen cut him off abruptly, but her smile was kind. "In the meantime, young prince, I must ask you to exercise more discretion and care. I can provide you with something to assist."

She closed her eyes, and the same blinding white light Endymion had seen on the beach when he first met Serenity flashed from the crescent moon insignia on her forehead.

The flash was gone as quickly as it had arrived, and, in its place, resting in the Queen's cupped palms, was a white domino mask.

"This is for you, Endymion."

A jolt of energy shot through him the instant he touched it.

He ran his fingers over the material that was somehow both hard and soft at the same time, unable to explain his immediate connection to the object.

"I know it looks unassuming. However, it is enchanted with Lunarian magic. As long as you are wearing this mask, your identity will be concealed."

Music and excited chatter echoed throughout the spectacular silver and white marble ballroom as Lunarian nobles swirled around in their finery. Enticing smells wafted from tables piled high with delicacies unique to the Moon Kingdom. Above the revelry, intricate crystalline chandeliers hung from the ceiling, casting a bright glow over the ball's guests.

Endymion noticed none of it. The princess was all he could see.

His heart hammered in his chest as he approached the dais. Princess Serenity sat next to her mother, her usual white and silver silks traded in for a dazzling royal blue lace dress that cinched at the waist and ended in a full flowing skirt. Her bright blue eyes shone brightly from behind an intricate red mask as she and the queen laughed together.

Endymion was hypnotized.

Mentally shaking himself, he took a deep breath and fell to one knee before the two, bowing deeply.

At first, he'd been worried the mask Queen Serenity had given him wouldn't stay on his face, but once he'd put it on, it was like an extension of himself, no more likely to fall off than one of his limbs.

Endymion rose and exchanged a knowing glance with the Queen.

"Dearest daughter," Queen Serenity began, an amused smile on her lips. "I met this young man earlier and think you may find him of great interest."

Endymion didn't miss the flicker of annoyance that passed over Princess Serenity's face. It was gone as quickly as it had come, replaced by a polite smile that didn't reach her eyes. He didn't let it phase him. "Princess, may I have the honor of this dance?"

Serenity nodded, and allowed Endymion to take her hand and lead her to the center of the ballroom. The mask's magic was stunning. Endymion wore his formal armor, something Serenity had seen him in countless times, and yet, she showed no sign of recognition.

She was every bit the perfect charming royal hostess-gracious, practiced, polite. But he knew her well enough to recognize that her demeanor was a pretense. Still, she enchanted him.

He couldn't help but grin as he took her hand in his and they began to dance. How many times had they wished they didn't have to keep their love a secret? That they could freely be with each other in front of the people of their kingdoms?

Serenity felt stiff in his arms, and Endymion absently brought her her closer, his long finger tracing a gentle pattern on the small of her back.

She sighed contentedly, then suddenly stiffened, pulled away with wide, alarmed eyes, and dropped his hand from hers.

"I-I have to go. Forgive me."

For a moment, Endymion stood in stunned silence, other partygoers exchanging questioning glances with each other at the princess' retreating form.

He followed her. Found her sitting on a fountain's ledge in the palace gardens, the sound of her ragged breathing accented by the soft splashing of the water below.

She looked up at him, eyes full of questions.

In two long strides, Endymion had closed the distance between them, curling his fingers in a familiar motion.

In his hand, he held out a perfect rose, its blood-red petals leaping out boldly against the Moon garden's silvers and soft pastels. Serenity's eyes flicked between the rose, to his mask, to the line of his jaw, before her voice came out in a breathless, hopeful whisper.

"Endymion?"

There you have it! So, some thoughts that inspired this/came to me while writing (though, honestly, this thing had a mind of its own): 1. We never get an explanation of the mask in the manga or Crystal, do we? I decided this is my answer to that. I have no explanation for the tuxedo though. 2. I think it's plausible that Queen Serenity would risk it all for her daughter's happiness. In my mind, Queen Serenity is a lot like Usagi, who puts everyone else's happiness first.

There's also kind of a sad, dark side there that is kind of the second meaning of the title - like Queen Serenity's encounter with Endymion and optimism that she has going into trying to make this radical change and proposing marriage between the two starts off a chain reaction (ie a domino effect) that leads to the kingdom's eventual downfall.

But goodness that's depressing, and this is supposed to be fluffy (though I think to some extent those dark themes are always going to pop up in SilMil stories that kind of subscribe to canon). But for now, let's enjoy their happiness!

Please please please let me know what you think!