Jiang Nian, a once-misunderstood city inspector, unexpectedly gains the ability to see a "danger countdown." After a subway accident, she joins hands with emergency safety expert Xu Anlan to track hazards from old escalators and crumbling buildings to public facilities, seeking evidence and eliminating risks amidst doubt. As the numbers light up time and again, the two gradually discover that this ability not only guards lives but also brings long-ignored safety issues back into focus.