What It Does
A path of moving water, drawn under the foot and held — the water carries, and the carrying is the whole argument, and the one who walks is the one who is still standing. It is the water school's answer to the air door's distance: the water carries where the foot says.
The Cost
Circle 3 · Water · Exchange: breath — casting time one round. The Exchange is the breath rung on the ladder in The Veil: the spell costs exactly as much as the spell is, and the meter pays the budget, not the cost.
The Failure
The current holds the shape a beat too long, and the water keeps the tension — the path is the one who is still standing, and the one who walked is the one who has to walk back.
In Stories
The journeyman's water spell; the one the camp casts when the ground gives out and the foot is the one who has to carry.
The door's scale anchor is Tidecaller, who casts it the way a hand casts a shadow — which is how a reader knows the shape of the thing, because the dragon does not think about it.