Interesting observation – a wall is literally a boundary and metaphorically a barrier to plot. Think of the first layer as the physical brickwork: sturdy, obvious, giving us a tangible limit. The second layer is the narrative texture – the characters’ perceptions of that wall, the rumors that it keeps out certain truths. Then there’s the psychological layer, where the wall becomes a symbol of fear or ambition, shaping motives and foreshadowing conflict. If you’re hunting the next breach, look where the layers start to overlap or contradict – that’s usually where a narrative crack will form.