An Group CEO Aurora develops a serum that can extend human life—instantly turning her into the world’s most hunted target. Every power faction wants it. Every assassin is coming for her. To protect her, the King of Assassins leaves the underworld. Bound by a promise, he becomes a simple security guard at An Group. But “normal life” never lasts. Now, the strongest man alive guards the world’s most dangerous secret… and every move he makes shakes the system to its core.