Underland

Down they go, through murky brambles in dusty plastic precip, probing the Earth for the great hole in the crust that would keep them safe.  Blackened shapes, tarnished trinkets, shrapnel fossilized by the erosion of civilization.  Sky pulverized into grimy sheets of ash, separated by red openings to the sky.  The Earth shakes, spewing fumes, gaseous souvenirs from ages before the darkness.  A girl holds a doll to her chest, a shield against semi-supernatural forces; a professor carries a map, ripped in places where it doesn't matter; others are parched and bleeding, their bodies swelling and receding, like the ancient moon-tide.

The entrance to the cavern shows promise, like most of them do; only this time, it's a hollow one, for the darkness there triumphs the one outside.  It's a long way down, they know it, but the chance for food and shelter at the bottom makes it worth the struggle.  In they go, several miners leading the way, their headlamps illuminating the walls.  The professor remarks on the lost languages of the writings sprawled on them.  Even he can't decipher their meaning.  There are pictures, however; the atomic symbol is one: an exclamation mark another.  A woman whose eyes are bleeding says that at least some ancestors cared about them enough to communicate.  A religious man says it's a sign from God, pointing out they must keep going, that any place is better than the surface.

He's right, so they carry on, down granite corridors of dread, the distant sound of explosions receding with every switchback through the cavern.  A steady dripping of water can be heard.  The cavern's made of limestone, that malleable canvas for caves, ripe of carbonate to shape their distorted topographies.  Stalactites hang like threatening icicles of teeth that the jaw of the cavern produced.  Down here, nothing exists but microbes that don't need sunlight or oxygen, at least according to the professor.  The girl thinks they'll be the only survivors after it's all over, if it ever is over- those invisible seeds of evolution that made it possible for bigger life to graze the fields of yore.

When they get to the vault, it's marked by a giant "X".  Below it is an oil drum with a skull and bones tattooed across it.  Exasperated, the survivors have nowhere left to go.  The only option left is to have the strongman try opening it, despite the blatant warnings.  For once, the religious man wonders if God has deserted them.  As he watches the strongman move the wheel, he hears a collective sigh from the group as it comes full circle, releasing a sound that Satan might have produced if they were at his doorway.  But it's not Satan.  They look upon a sea of nuclear waste, suspended in a sea of magma.  The magma is churning broken rods that once held the waste deep underground, so nothing would ever become contaminated by this vast storage of radioactivity.  The first words come from the professor, who remarks that the increased pressure from underground eruptions must have caused them to sever, that the waste must have had a profound impact on the world below, radiating strongly enough to alter the crust in ways never predicted.  Out it erupted into the atmosphere, creating a fallout that didn't require the crimes of war, only a willingness to produce prolifically, inverting the underworld from within to without.

They all suspect there is no escape.  Only the professor knows for sure.  The girl drops the doll and takes the map, leading them back through the tunnel, holding it like it was their last ounce of hope.  In despair, the religious man declares they are the last humans on Earth, that this is a condemnation of mankind, a Judgment Day.  The professor counters, saying there are others in the south, sheltered from the radiation.  If only we lived there, thinks the red-eyed woman, if only we'd heeded their warnings.  Where the underland meets the overland, they see water pouring through the entrance.