Coma, published in 1977, is Robin Cook's breakthrough novel that established the "medical thriller" genre, following medical student Susan Wheeler as she investigates a series of patients falling into comas after routine surgeries at Boston Memorial Hospital, uncovering a sinister conspiracy involving a black market organ trade. The story combines medical detail with suspense, as Wheeler discovers a pattern of anesthesia tampering and a hidden facility where comatose patients are kept for organ harvesting.