Toba

The accident was a mountain. One morning it stopped being a mountain and became a sound. The sound was loud enough to shatter rock a hundred kilometres away. The ash that followed — not fire, not flood, but ash — rose so high it bent the sunlight away from the Earth for years. Maybe a decade. Crops that didn't exist yet would have failed. Forests went grey. The sky at noon looked like dusk. We know this because the ash is still there, a pale stripe in cores drilled from the seafloor, from ice in Greenland, from lake beds in India — the same stripe, everywhere, the same winter pressed into the ground like a thumbprint. And underneath that stripe, something strange: the genetic signatures of every human alive today converge. Not because we all lived near Toba. Because almost nobody survived. The best guess is a few thousand people — some say fewer. The whole human species, the entire future, pressed down to a group that might have fit inside a single valley. Every person you have ever met, every face in every crowd, traces back to whoever those people were. We don't know their names. We don't know what language they spoke. We know only that they made it through the dark, and we are the reason they bothered.