Twenty-eight-year-old Sean McGillin is the picture of health, until he fractures his leg while in-line skating in New York City's Central Park. Within 24 hours of his surgery, he dies.

Newly minted chief resident at Boston Memorial Hospital Noah Rothauser is swamped in his new position, from managing the surgical schedules to dealing with the fallouts from patient deaths. Known for its medical advances, the famed teaching hospital has fitted several ORs as "hybrid operating rooms of the future" - an improvement that seems positive until an anesthesia error during a routine procedure results in the death of an otherwise healthy man.

Trying to find some normalcy during the COVID-19 pandemic, Brian Murphy and his family are on a summer excursion in Cape Cod when his wife, Emma, comes down with concerning flu-like symptoms. But their leisurely return home to New York City quickly becomes a race to the local hospital as she suddenly begins seizing in the car. At the ICU, she is diagnosed with eastern equine encephalitis, a rare and highly lethal mosquito-borne viral disease seemingly caught during one of their evening cookouts.

They called it "minor surgery", but Nancy Greenly, Sean Berman, and a dozen others - all admitted to Boston Memorial Hospital for routine procedures - were victims of the same inexplicable, hideous tragedy on the operating table. They never woke up...

Lynn Peirce, a fourth-year medical student at South Carolina's Mason-Dixon University, thinks she has her life figured out. But when her otherwise healthy boyfriend, Carl, enters the hospital for routine surgery, her neatly ordered life is thrown into total chaos. Carl fails to return to consciousness after the procedure, and an MRI confirms brain death. Devastated by Carl's condition, Lynn searches for answers.