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!
Yes... But why tennis? What in the 
world is an underground tennis club?
نعم... لكن لماذا كرة المضرب؟ 
لماذا هو نادي كرة مضرب سرّيّ بالضّبط؟
Schön und gut, aber warum Tennis?
Und was ist ein Untergrund-Tennisverein?
Pero ¿por qué tenis?
¿Y por qué un club de tenis clandestino?
Pero ¿por qué tenis?
¿Cómo que un club de tenis clandestino?
Oui… mais pourquoi du tennis ?
Capisco...
Sim, mas por que tênis?
Por que tem um clube clandestino de tênis?
Угу…