A controversial safety intervention, rapid response systems (RRS) do not appear to improve clinical outcomes despite being extremely popular among hospital staff, who point to many individual cases where RRS have been beneficial. This ethnographic analysis of RRS at two British hospitals describes the complex interplay between patients, nurses, and physicians when a patient is acutely deteriorating, and provides considerable insight around how systematizing care with RRS can identify underlying quality problems and issues with safety culture. The study provides an excellent example of the role of context in implementation and ongoing oversight of patient safety interventions.