•Why it earns a slot
Why it earns a slot: it stages denial as architecture, seven sealed rooms and a hammered-shut gate, then lets the thing being kept out arrive dressed exactly like the thing itself.
A prince locks a thousand nobles inside a walled abbey to outrun a plague, and the plague walks in anyway, dressed for the party.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.