Yue Liuying was just a simple and playful girl before she was forced to marry Ling Qiye and be a concubine by her foster brother. Yue Liuying didn't want to be a spy, but couldn't get rid of the control of her foster brother, so she had to find another way to live. On the wedding night, she planned to poison the bridegroom to fake death so that she could escape from the Ling family and regain her freedom. However, on the day of the wedding, she and Ling Qiye both had their own thoughts and end up being "Mr. and Mrs. Smith" in ancient times. The innocent Yue Liuying couldn't fight Ling Qiye, who has been doing business for many years. Being played around by Young Master Ling, and threatened with the repeated poisoning of her foster brother, she has no choice but to temporarily let go of the idea of running away and wait for a chance in the future.