A global climate catastrophe strikes without warning, plunging human civilization into the abyss within 24 hours. Temperatures plunge by twenty degrees, deadly acid rain and hail tear across the sky, and devastating hurricanes sweep over the continents. The authorities' vague “climate anomaly” announcement becomes the final faint echo before civilization's collapse.
Su Yuan, a meteorologist, experiences hell descending firsthand at the heart of the disaster: the Nanjing City meteorological station. Amid the ruins and raging natural disasters, he receives a chilling encrypted message from an unknown source: “Beware the rainbows. They are not light.” Along with the violent mutation of some unknown specimen in the station's deep-level laboratory, the warning becomes the only clue he carries as he flees to the meteorological station's central fortress, buried deep underground.
In the sunless, resource-starved underground fortress, Su Yuan and a handful of survivors eke out a living for three months on canned food and the cold readings of their instruments. Hope fades with time, while internal conflicts and unknown horrors from the deeper levels close in one after another. When the government's radio signal is finally replaced by an endless hiss, the world seems to have died for good.
Yet when Su Yuan gathers his courage and raises the fortress's observation shutter for the first time in three months, he sees nothing like the dawn he had hoped for. The acid rain has stopped, and the sky is an eerie, lifeless gray-white. The city has become a frozen ruin covered in a slick carpet of fungus. And at the edge of this silent world, a gigantic rainbow beyond all imagining slowly arcs across the sky.
