THE SKY IS BURNING. With Rat critically injured protecting him, Shion finally returns to NO. 6. But what he finds there is not the tranquil utopia he left behind, but a city in the grip of panic and chaos. As the ""holy city"" collapses in on itself, Shion and Rat put the future of humanity - and their future together - on the line in the shocking final volume of NO. 6!