Wondrous item, rare
Setting the ward takes 1 hour and its own four nails, driven into the leaf or the frame of a door, gate, hatch, or shutter no more than 10 feet in any dimension. The face bearing the device is the warded side. Prising a nail unmakes the ward, and the nails can be drawn from the unwarded side only.
While the ward is set, the door cannot be opened, forced, unbarred, unhinged, lifted, or cut through from the warded side. A key turns and the door stays shut; magic that opens or unlocks fails; while the four nails hold, door and frame are immune to all damage, and the wall must come down instead. From the unwarded side the door opens exactly as it did before.
No water passes the doorway from the warded side while the ward is set, at any head of water, and the frame does not weep.
The ward does not know what a room is for. Set upon the inner face of a door, it holds that door shut against everything inside the room, and the office it came from did that twice and entered both nights in its book.
Source: Provenance — The Quist Sale