Martin has written a newspaper article noting that Interpol Agent David Matson (Murray Rose) is to visit the Lane family. David is a good friend of Cathy's father and is staying over for some rest and relaxation. Patty becomes paranoid of the fact a spy is being hosted at home. Most of all, David wishes to see a woman from New York he met and is attracted to, Irene (Hannie Landman). The two playfully talk as if major spies. Irene returns his calls as "The Lady in White" and Patty suspiciously takes a message for David. Consumed with curiosity, Patty and Ross go to the doctor's office where Irene works and overhears her talking with a friend how she doesn't plan to let David "slip through her fingers this time" and how she has to "work fast". Patty misunderstands it for her being a double agent and tails the two as they go about the city, with comical complications.
Certainly a rather silly episode, but a fun change of pace and one of the funniest episodes.