The world is overrun with monsters called Nemeses-and a young boy infected by one will stop at nothing to defeat them all!

Evil creatures called Nemeses fall from the skies and the only ones who can fight them are Wizards-infected ones who survived a Nemesis's corruption. Seth, one of these survivors, vows not only to fight the Nemeses, but to find their mythical nest, Radiant, and destroy it!

Seth has been thrown into an Inquisition prison to await execution. Meanwhile, after acquiring the unwilling services of Dragunov-a once prominent Inquisition officer on the run from his former colleagues-the equally mysterious entity known as Grimm sets out to free Seth. Knowing nothing of this, Seth ponders unexpected truths about himself and some old friends even as he tries to figure out a way to escape. He is also unaware that another friend, Melie, has succumbed to an alternate persona that's led her to join the Inquisition's main foes, the desperate and violent Domitors!