The secret files called the Zacharis Dossier may cause a war between the East and the West. In order to obtain a painting that is supposed to be the hiding spot for these files, Loid and Fiona enter an underground tennis tournament run by the owner of the painting, Campbell. If they win, the art piece they're after will be presented. Loid and Fiona enter as a married couple and play various skilled players including pro players!

The underground tennis tournament is finally heading to the final match. The Campbell siblings that Loid and Fiona are up against are playing dirty, as they have altered tennis rackets as well as the staff helping them out. But the spy pair from WISE overcome one obstacle after another and Loid deals the final blow! But right after the match, the State Security Service finds out about the dossier and infiltrates the tournament...