Maaya is a teenager who can see ghosts, and she and her three friends get by on the poor streets of Sark by sealing away troublesome spirits under the direction of a deceptive, malicious holy man. Accompanying them is a ghost named Saber, Maaya's long-time friend. Maaya doesn't concern herself with affairs of the world, but after an entire street of people goes missing without a trace and whispers of war begin to reach her ears, Maaya decides it's time to investigate.
Maaya soon finds herself in over her head as she confronts a wave of faceless ghosts that terrify even the dead. Driven on by rumors of a mysterious weapon that can make entire cities vanish in an instant, she and Saber start their journey across the world to find out how to stop it. All the while, Maaya slowly begins to fear that these ghosts aren't just mindlessly killing innocents - and that they may be chasing her instead.
She wondered how they could do it – how they could kill so effortlessly and show nothing for it. There was no emotion, no reaction whatsoever. It was inhuman, and it disturbed her. They wandered through the world as if they were completely unaware of it; this was not malice that drove them, and that made them harder to fight. They were a force of nature, wild and dangerous as an ocean storm, and to fight them was as fruitless as fighting water. But the sight of them now instilled something in Maaya that no tempest ever had. She paused, unable to take her eyes away from them, but this time it was not because she was under their control.