The winged Lyrinx are conquering Santhenar, each engagement weakening the faltering human resistance. The Aachim watch and wait - their invasion diverted in favour of a treacherous temporary alliance against the Lyrinx threat. The last hope lies with a small yet determined band of fighters, led by disgraced Scrutator Xervish Flydd, who had escaped from the ruling Council's brutal retribution. But Xervish and his supporters have now been condemned to a painful death for supposed treachery ... However, two rebels are missing: Tiann - a geomancer of immense power, and arch-traitor Nish. They could make the difference between victory and certain annihilation.