Her world freezes in the instant that it begins to hurt.
Just to the left of her spine, her back has been arrested in an explosion of pain, like a photograph of a blooming flower. It's a bizarre feeling—neither a throbbing pain nor a constant one, but a moment of agony stretched infinitely far and thin. The heartbeat between touching a hot stove and jerking away, forever.
Her friends are frozen in shock, reaching for her, unbalanced beyond the permission of gravity. The dust motes have stilled in every shaft of light.
Aerith cries out to the Planet and is surprised to hear her own voice. No part of her body has moved to produce it.
"Hello, child," says a voice in her ear. A woman's, steel-cold and heavily accented in a way that she can't place. Long violet fingers, ending in longer claws, reach from behind to cup her chin, but there were not present a moment ago and are not part of the moment in which Aerith's nerve endings are still stuck.
The clawed hand slips down Aerith's jaw and down out of her sight. With a noise like talons clacking against the altar, a figure of red and black, exposed pale skin and variegated markings, interrupts her view of her frozen friends. The stranger is monstrous, winged and clawed, but the face that closes in on her is human, its long horns only complex arrangements of hair. There is something of Sephiroth in the white hair and pitiless eyes.
Aerith knows how to deal with monsters. "Is this your doing?" she asks, tongue stuck fast to the roof of her mouth.
"This is the merest tip of my power. I hold time as easily as you hold your breath." An unpleasant smile twists the stranger's mouth as she taps a claw against Aerith's insensate lips. "Be honored, mortal girl. Few eyes behold the glory of the Sorceress Ultimecia and are not burned away."
Few have prayed for Holy, or grown flowers in a shadowed slum, or been the last of a ancient race; Aerith has always been "few." She wishes she could narrow her eyes. "What do you want?"
"The better question," Ultimecia replies, "is what you want. I have come at the moment of my end to give you the gift of beginning. I offer you power beyond your imagining, to reshape your doomed world and take your place in the succession of sorceresses."
She makes promises like Shinra. Aerith cannot be tempted as long as she remembers this. "Well, I don't want it. I'm saving the world right now. You should go find a different one."
Ultimecia laughs, folding her massive ravens' wings behind her back, and circles behind Aerith. "You may lie to yourself, child, but not to me. I will show you what you desire." The tips of claws appear in Aerith's peripheral vision and rest against her temples.
The altar and the city and the darkness ripple away. Aerith still kneels, still cannot move, but now her knees press into lush grass beneath the dazzling sunlight. Her friends dance in circles, safe and happy, laughing.
Cloud bows before her, gazing up with naked admiration. He is more than a friend, more than a protector, more than a lover; he would end worlds for her, would cut out his own heart at her whim. She is the breath that fills his lungs. She is the sea into which his thoughts flow.
The sky above is an unmarred blue, and she rises into it to watch all the world at once. Flowers grow between Sephiroth's bones as his soul melts into the Lifestream. The dark heart of Midgar cracks under the pressure of ten thousand trees laying down new roots. From the fertile earth, generations of dead Cetra rise, glowing green as their lives flow back to them from below.
Aerith watches it all, Ultimecia's black feathers intruding on the edge of her vision, until it fades back into the underground darkness.
"You're not the first one," she says, "to make this kind of mistake."
Ultimecia's scowl is audible. "What?"
"I grew up in the slums. I'm not stupid." It's better, really, that Aerith's body is out of sync with her now; fear can't cloud her brain or shake her voice. "Do you really think you can trick me by promising me what you think I want?"
"Your mind is bare to me." Ultimecia's claws curl possessively over her cheeks, just beneath her eyes. "Your desires are simple, naked, squirming things."
"Then you didn't dig deep enough."
The claws swipe away; perhaps if time still flowed, they would have drawn blood. Ultimecia's face fills Aerith's vision, tawny cats' eyes narrowed, dark lips pulled into a sneer. "Have you fooled yourself into desiring this? To die here, knowing that you have failed and all your world is to follow?"
Has she failed? She felt, for an instant, an electric connection to the Planet, and something like triumph surged through her at the sight of her friends. But the only echo of feeling with her now is the pain clustered in her back, ready to rip her open. The Planet's salvation teeters on a razor's edge, on whether an instant is enough.
She's going to die. For the first time in her life, she feels too young.
"Such a waste, child." Ultimecia presses her lips to Aerith's forehead, and the place they touch falls briefly back into time and feeling. Her lips are cold. "Open yourself to me."
Cloud is not at Aerith's feet; he is hidden by Ultimecia, lunging forward in horrified incomprehension. She would rather remember him in the dimness of a gondola, face lit a thousand colors by the fireworks, but she also remembers his face twisted with rage as he attacked her. Everything is tangled. Everything must be. What monster would tear out every strand of life and attempt to weave a new reality from the corpses?
"No," Aerith says, and the Planet speaks with her; her body bursts with sensation as the Lifestream blazes up through her. Two screams, Ultimecia's and her own, and time lurches forward again.
Her heart beats. She focuses on that, as pain bursts through her body and steals her sight, until she is able to let go.