When the United States joins Israel's war on Iran, the first missile that reaches Isfahan takes the radiology annex of a children's hospital - and with it the husband of Dr. Shirin Farahani, a Central Bank settlement expert who has spent twenty-six years inside the machinery of global money. Grieving, methodical, and incapable of pretending otherwise, she begins to see the war not as an event but as a system: beneath the bombs runs a quieter, more decisive layer, the invisible grid of trust by which the world's banks agree what a number is worth. And she knows, because she helped write it, exactly where its doors are.