Loid and Fiona temporarily depart their domestic lives to embark on an intense, undercover mission centered around an underground tennis tournament hosted by a wealthy art collector. Their objective is to secure the legendary Zacharis Dossier, a secret document rumored to contain historical wartime secrets capable of reigniting a full-scale conflict between the East and West. To win the prize, the two elite spies must disguise themselves as a married couple and defeat a series of physically augmented, cheating professional players on a high-tech court. Back at home, Yor continues to harbor severe anxieties about her position in the family, leading her to seek cooking lessons from a coworker to surprise Loid.