Retired secret guard "Daniu" was sold by his mother into the Prime Minister's Mansion as a maid for ten taels of silver. The Prime Minister's Mansion was ransacked the next day. She became the only servant to be arrested and was imprisoned together with Qi Xuan, the "prime minister's son". After escaping, the prince showed up and revealed that Qi Xuan was actually the ninth prince who had been betrayed, and hired Da Niu to protect him. Daniel seems to be greedy for money and confused, but in fact he has already seen through the overall situation. She teamed up with her master, colleagues and the Ninth Prince to set up a shocking scam using herself as bait. In the end, she not only killed the hypocritical prince with her own hands, but also helped the Ninth Prince Nangong Shen ascend the throne, subverting the entire secret guard system, winning the right to retire freely for all her peers, and opening a butcher shop as she wished.
