Luca serves as a bugler for a mercenary outfit, dreaming of abandoning warfare to pursue music as a true artist, a maestro. He bears the mark of the mysterious Branch-hexed, and he has an odd talent: he can see the sound his bugle makes. Against his wishes, he is pulled into a war of enormous scale. The year is 1294 of the Arboral calendar, and nine giant towers called the Spires loom over the world, leftovers of a vanished civilization that still hold lost secrets and potent knowledge. Nations fight to claim them. The result is fantasy action with a psychological edge, pairing one reluctant musician's ambitions with large-scale conflict.