Shen Lang, once the King of Mercenaries who struck fear into the hearts of people overseas, has grown tired of ten years of bloodshed and quietly returned to his homeland to live an ordinary life. Before he could even finish a bowl of beef noodles at Jiangcheng's night market, he stumbled upon Su Qingyan, the president of the Su Group, being cornered by thugs. After casually coming to her rescue, a twist of fate led him to join the Su Group as a security guard at the west gate. Flip-flops, an old T-shirt, and a broken fan blowing inside his guard booth—nobody knows that this seemingly laid-back security guard once terrified intelligence agents from countries around the world.