In South Korea's top hospital, Hyeri, the emotionally distant cardiothoracic surgeon, is known for her flawless technique but avoids personal connections. Soobin, a kind-hearted anesthesiologist with a past of living in her older sister's shadow, is eager to prove herself despite her quiet demeanor. When the two are forced to work together on a high-stakes surgery, they begin to form an unexpected bond, though Hyeri's walls remain unyielding. As their professional and personal lives intertwine, they confront the trauma and insecurities that keep them from fully opening up to each other.

Jaeyi's world shifted the day her father married Seulgi's mother, bringing an uninvited rival into her home. Seulgi, the quiet farmer's daughter with an unsettling brilliance, quickly became the only person who could challenge Jaeyi's place at the top. At first, it was just competition, but soon Jaeyi found herself watching too closely, noticing too much obsessing. Seulgi never seemed to care, always focused, always just out of reach. But Jaeyi wasn't sure how much longer she could stand being ignored.