The Hong Kong branch of the spy organization to which Yu Xiaojiao (played by Gao Haining), agent number C9, belongs exploded for no reason, and Xiaojiao has lost contact with the headquarters since then. Later, Xiaojiao married Gao Dajin (played by Ma Guoming), a loyal and honest vegetable seller. She was busy taking care of Dajin's troublesome but warm family every day, and lived an ordinary and happy housewife life for four years. Unexpectedly, her former agent partner B3 (played by Lai Lok Yi) suddenly appeared and invited Xiaojiao to investigate the cause of the explosion of the spy branch and to retrieve the VT nerve agent that disappeared after the branch was blown up. From then on, Xiaojiao began to live a double life as a housewife and an agent. Dajin accidentally learned about Xiaojiao's identity as an agent and was unable to accept it for a while. During the Cold War, Dajin realized his feelings for Xiaojiao and sincerely accepted Xiaojiao. Soon, Xiaojiao discovered that B3 was actually a traitor who blew up the spy branch and used Xiaojiao to seize the VT nerve agent for profit. Xiao Jiao and Da Jin, a couple who have no special agent skills, work together to fight against B3 and maintain world peace!