A future Earth is devastated by the "Angel Plague," a pandemic that induces apocalyptic visions in the afflicted, even as it ossifies their bodies into dead, seraphic forms. A cult-ridden, army-backed medical unit journeys into the heart of a dying Asian city accompanied by Sera, a mysterious girl linked to the phenomenon itself. Have they come here to kill or cure? And is the Angel Plague a withered branch on the tree of life, or somehow a new flowering of existence?