Snagling Catch Window

A picture window of the fens: build nine blocks in a 3 × 3 square in a wall and the catch appears — a silver fish, a feather, a shell and an opaline shard drifting to whoever snags them, a hook reaching in, and the knotted cord the Snaglings count their catch on. At night it glows faintly (light 3). A block on its own is river-blue leading in a wicker edge.