Due to a canceled lecture, Frasier and Niles change their plans, but wind up at the same restaurant where their father Martin is dining with an old family friend, Marion Lawlor.

After piecing together bits of Niles’s boyhood journal, the brothers conclude that their father and Marion had an affair years ago. When Frasier confronts Martin with their suspicions, he admits to the liaison.

Later, Marion informs Frasier that it was his mother and Marion’s husband who had the affair. When Frasier apologizes to Martin, who lied to protect his son’s memory of his mother, the men realize that the one common bond they share is that both of them were cheated on by their wives.