Lissa Aires checked the time on her phone: 11:43 p.m. Night shift at St. Maren’s meant the hospital breathed differently after dark—quieter, but sharper. The fluorescent lights hummed above the nurses’ station as Lissa capped her pen and pulled her cardigan tighter. Tonight she was the only registered nurse on the medical-surgical floor; the usual team was stretched thin after a busier-than-expected evening.