In the operating room, Dr. Jinhyeok Lee is flawless—unyielding, brilliant, and untouchable. But outside, he's a ghost to his family and loved ones. He misses everything, even his mother's final moments. By the time he understands what he's lost, it's too late… until it isn’t. He wakes up 27 years in the past. Now armed with a lifetime of memories, Jinhyeok vows to live differently. But peace won't come easy. Old rivals, new battles, and countless lives await. Scrubs on. Lights up. Scalpel ready. And this time, Primum non nocere.