A new ice age has dawned on Earth, and humanity is facing its own extinction. Billions of people abandon the ice and gather in the last habitable zones of the planet. They can escape the winter but not human nature: war is coming.

In orbit around Earth, a group of scientists make a final effort to discover why the planet is freezing. However, none of the climate models they test make sense. Then, among the flames of the sun, they spot something fleeting, something that shouldn't be there...