The Southern Wasting emptied the southern third of Deo Esari's titan-bone country in a single season, around 3176 SD, and the ground has stood closed ever since. It is the disaster the codex elsewhere calls only the contamination, because that is all the Titanic Priesthood has ever let anyone call it.
What the priesthood did
The grounds at the southern end of the Kelder foothills had been worked for bone as long as anywhere in Deo Esari. The richest of them lay around Tomgryir Eror, and it was there, by the priesthood's own buried account, that it began. A harvest crew cut into a titan that had never finished dying.
The titans died in many ways after the Ezz Rift drove them mad. Most that remained in Alaria killed themselves; their blood dried to red powder in the rock and their bone went still and inert, which is the state every harvest depends on. One in the southern foothills had done neither. It had come to rest in something between death and a long dreaming, its blood never dried, the Deoric charge that had once animated it never gone quiet. The crew that opened it expected inert bone. What they struck was a wound that bled, and what bled out of it was raw Deoric charge, the reality-shaping force of the creation-language loosed with no rune to hold it and no titan-matter to buffer it.
How it killed
The charge went where water goes. It seeped from the breach into the springs and the shallow groundwater that fed the harvesting villages, and from the water into the people who drank it and the crops that grew on it. Deoric is the language that authored the binding of soul, spirit, and shadow; loose in a living body in this raw form, it frays that binding from within. The grown wasted, a slow unspooling that ordinary medicine could neither name nor slow. Children conceived on the poisoned ground were born with the binding malformed, born wrong in ways the old records describe and never explain. The south died across a single year, family by family, until the priesthood evacuated what was left.
It does not fade. This is the part the priesthood understood first and concealed hardest. Titan-matter holds Deoric charge without decay, and that imperishability is the whole reason titan bone is precious; it is also why the south will never clear. The breach has never closed. The titan does not rot, so it does not stop bleeding, and what it bleeds re-poisons the springs faster than any water could carry the charge away. Not in a mortal span, not in many. The southern grounds are not recovering. They are simply what they now are, and what they will stay.
The seal
The priesthood evacuated the south, ringed it with warning markers, and sealed the cause in its archive at Thillesari. The public record kept only a wasting sickness of unknown origin and a quarantine that might lift if the ground ever proved safe. The decision to bury the cause was not made to spare the dead. It was made to spare the order. A priesthood that admitted it had killed its own south by cutting a titan it should never have touched would not have survived the admission, and the bone that the closure made scarce would not have stayed so dear. Two centuries on, the seal still holds. The full shape of what it protects is set out in the Titanic Priesthood's own entry, and the one priest who mapped the whole of it and chose silence has his.
What is still true
Four named grounds remain closed behind the markers: Eshbya Hills, Tomgryir Eror, Carya Nairn, Kirthdron Soytas. Their villages stand intact and empty, belongings where the evacuation left them. The titan still lies breached and dreaming under the southern foothills. And the pressure the Wasting created has not eased but tightened. Cutting the south from the supply is why titan-bone prices have climbed without rest for two hundred years, which is why the argument to reopen the south grows louder every year, which is why the priesthood guards a line it refuses to explain. A crew that pushed back into that ground for bone would be cutting toward the thing that emptied it.