"Nyxathena Nightingale and Kiero Crestwood, before the High Court of Celestia, you are hereby claimed as oath-partners from now until the end of eternity." Denver, High Witness of the Court of the Acclaimed, announces into the silent, elaborately decorated room. Thea and Kiero stare at one another, their gazes a mix of distaste, uncertainty, and defeat.

The two shift closer, their hands connecting in a firm grip, and the warm, sticky substance between their palms drips to the ground in a splatter of crimson. No turning back now, a blood oath could never be broken. 

*** Five years later ***

"Kiero!" Thea cries, her voice carrying through the caverns as she unsheathes her blade. Kiero jerks, stumbling back from the water's edge and drawing his daggers in alarm. He casts a wary glance around the cave, his eyes locking on the girl caught in a ring of figures. 

They descend on her all at once, their oily black wings flapping violently and an ear-splitting shriek erupting from their open mouths. Keiro yells in outrage, thrusting his daggers through the air in one fluid motion and leaping into the battle. Both blades cut through flesh and black liquid oozes to the ground, the creatures screech and turn red eyes on him. 

Unarmed, Kiero dodges their blows as he advances, ducking and blocking, using his body weight to push them back. A glint of silver catches his eye and he hurls himself toward it, feeling his fingers wrap around the hilt of the blade. One of the creatures lunges for him, Kiero twists to his back and brings the blade up as a warm body smelling of rot settles heavily on his torso, going limp when his blade plunges through its stomach. He grunts and wiggles free, wiping the black goo from his hands and whirling to face the next assailant. 

"Thea!" He yells, eyes searching frantically in the darkened chamber, their torches having been snuffed out in the scuffle. Something shifts in his periphery and he reacts on instinct, feeling the pressure of another body as it collides with his blade and sags to the ground before him. "Thea, where are you?" Kiero barks, advancing several steps to where he'd last seen her. 

More figures as Kiero defends himself, slicing and hacking at them as they charge. One, two, three more bodies drop before a heavy silence falls over him and he remains perfectly still, ears perked and muscles taut. "I'm here," comes a quiet voice, Kiero whips around to face the voice. 

She's bent over the edge of the water washing her hands and face of the slick, black substance. "How did they find us?" Thea continues, shaking her hands and pressing them into her jeans with a frown. Kiero sighs with relief and puts his blade away, dark eyes scanning the space in search of the other. 

"I don't know, but we should move on. More Wraiths might come when their friends don't return." Kiero reasons, spotting the second dagger and hastily recovering it. To his side, Thea mutters a quiet word and a ball of fire bobs before them, pulsing erratically. 

"But the bounty, we haven't found the crystal yet." Thea argues, her silver hair and blue eyes fierce in the orange light. Kiero levels a look at her and scowls. 

"It doesn't do us any good if we're dead." He snaps back, grasping her hand in his, feeling the X drawn into her palm that signified their bond and tugging her forward. Thea relents with a grumble, falling into step beside him. The globe floats before them, illuminating their path in strobes of shifting lights. 

Kiero hated the caves, no matter how many times he and Thea were sent into them to recover artifacts and treasures he never got used to it. The way the shadows skittered along the rocky walls and the sounds that seemed to come from nowhere and everywhere at the same time. 

"This is the last time Roderick sends us down here, they are plenty of bounties in the forest." Kiero mutters, casting Thea a sideways glance. 

"The forest is easy, too many hunters out there already. No one dares enter the caves." Thea scoffs, her face shifting into an easy, arrogant grin. She enjoyed this, he knew, Thea always had. That was why Roderick had forced him into the blood oath, to keep a leash on his little sister and torment Kiero with a life he didn't want in the process. 

"What will we tell my brother about the crystal?" Thea remarks after several silent minutes as the cave entrance comes into view, a large, barely discernable rock rolled into place against a narrow slit. Kiero shrugs uncaringly. 

"That it's already been claimed, he won't question you." Kiero offers, his chin jerking in her direction. Thea frowns and crosses her arms against her chest, watching as Kiero struggles to roll the rock. 

"I won't lie to him, Kiero." Thea barks, angered at his insinuation. Kiero grunts and manages to force the rock aside, casting moonlight over Thea's scornful features. 

"You can and you will, I don't intend to come back to these caves. Roderick has ruled with an iron fist long enough, I'm tired of cowering." The sound of her blade screeching free brings Kiero up short. His hands drop to his daggers and he pivots slowly around, his eyes locking with hers in surprise. 

"Don't speak of him that way." Thea seethes, her body tense as she crouches into a defensive stance and levels her blade at his chest. Kiero gawks and tilts his head to the side, brows knitting together in confusion. 

"Thea, what are you doing?" Kiero questions, a note of warning in his voice. She was his oath-sister, she couldn't betray him. Not like this. Not ever. 

The girl laughs, a dark and humorless sound. 

"I've listened to you whine about Roderick for five years, Kiero. I'm tired of it, you've never enjoyed this life. The luxury of our status, the respect from the people. You can't see past this!" She arcs her arms wide, gesturing to the caves at her back. 

Kiero knew she was right, he hated the long weeks in the caves, the endless darkness, and the searches that never seemed to end. All for a crystal or a fish made of gold. Always something stupid. 

"You're weak and I've dragged you around with me long enough." Thea bites out, voice like ice and steel. Kiero backs up a step, noting the murderous gleam in her eye, and slowly grasps his daggers. 

"I don't want to fight you," he whispers, facing off with Thea in a slow circle. The girl curls her lips in disgust and rolls her eyes. 

"You never want to fight." She accuses and lunges, Kiero quickly draws his blades and raises them just in time to block her attack. The screech of metal permeates the air and the hairs on Kiero's neck stand on end. Thea rears back and winds up for another blow, but Kiero gives her no time to recover and slashes one blade across her abdomen. Thea inhales sharply and stumbles, but quickly recovers. She strikes Kiero with the hilt of her sword and he falls back, head swirling from the blow. 

From out of the gloom, Kiero just barely makes out movement, but his head is too fuzzy to speak out as they sneak up behind Thea. His oath sister's blade rises over her head, ready to plunge into him, but she goes suddenly still. Silver eyes widen with pain and shock, then her head rolls off her shoulders. 

"Kiero," an authoritative voice says, Kiero sputters and surges backward as Thea's body falls forward. He climbs to his feet and side steps as her head lands near his feet. Then, slowly, his gaze lifts to the figure. 

The Dark Pixie leers down at him, his ugly amber eyes cold and deadly. He steps forward and squares his shoulders, hands dropping lightly to his sides. Kiero gulps and spares Thea's body one last horrified glance. 

"It seems my sister was getting a little carried away, she never was satisfied being second to me." Roderick announces, looking down unconcerned at Thea's severed head. "You, on the other hand," his gaze lifts then, and Kiero sees the ice in his stare, "are too weak to fight back." 

Kiero pinches his lips together and sheathes his swords, mind racing with what to say. Roderick watches him for a moment and laughs, turning and gesturing for Kiero to follow. "Come along Kiero, let's find you a new oath-partner so that you can go back to the caves and retrieve my crystal, shall we?"