What It Does
The ground closes over a line — the road, the wall, the gap — and the earth does not move, so the earth buries. It is the siege spell of the school: the ground is the argument, the supply is the ground, and the ground is the one who decides which side of the buried line the camp is on.
The Cost
Circle 4 · Earth · Exchange: reagent (iron, named) — casting time two rounds. On the ladder in The Veil, the reagent rung is the price, and the meter pays the budget while the exchange pays the spell.
The Failure
The iron is named wrong — the reagent is the forge's, not the one the spell wants — and the ground closes, and the ground closes over the one who is already the road.
In Stories
The master's earth spell; the one the camp casts when the ground is the argument and the supply is the one who has to decide.
The door's scale anchor is Stonewrought — the dragon casts it without thinking, which is how a reader learns the shape of the thing.