"Stop! By the Keys I hold, I order the Nothing to stop!" is a commanding statement from the character in Garth Nix's book Superior Saturday. It reflects a moment where a character uses their power or authority to prevent an encroaching force of emptiness or destruction from advancing further.
This quote emphasizes the urgency and determination of the character to protect their world, specifically a house or place of importance, from being consumed by the Void. It showcases themes of resistance and the wielding of magical or symbolic keys to maintain balance and safety amidst chaos.