Sun which made Earth flourish for billions of years, once became a source of extreme radiation. Destructive radiation produced by solar flare was noticed too late - not hours remained, but minutes. You have 30 minutes to get to the nearest of InterShelter bunkers which were created in fear of nuclear war. The situation is somewhat complicated by the fact that very few shelters exist and one rescue capsule has fifty applicants. Natural selection will show ones worthy of salvation, and others will suffer in the scorched desert forever.