One of the chapters in the Second Epoch consists of a letter from Mr. Fairlie, in which he rather unwillingly gives Walter his account of various events, including his interactions with Count Fosco. The first time they meet, Mr. Fairlie assumes that Count Fosco has come to ask him for money. This is an instance of dramatic irony, as Mr. Fairlie's assumption is based on xenophobic distrust but nonetheless turns out to be entirely correct. Mr. Fairlie does not know this, but many of the story's events are propelled by the schemes that Sir Percival and Count Fosco hatch to get their hands on Laura's inheritance.
Is it necessary to say what my first impression was, when I looked at my visitor’s card? Surely not? My sister having married a foreigner, there was but one impression that any man in his senses could possibly feel. Of course the Count had come to borrow money of me.
‘Louis,’ I said, ‘do you think he would go away, if you gave him five shillings?’
Louis looked quite shocked. He surprised me inexpressibly, by declaring that my sister’s foreign husband was dressed superbly, and looked the picture of prosperity.
The reader knows that Count Fosco is not there simply to borrow money from Mr. Fairlie and also that he would not have gone away if Mr. Fairlie's valet Louis gave him five shillings. That being said, the reader also knows that while the Count may look "the picture of prosperity," he is in deep money troubles. Ultimately, Count Fosco has shown up at Limmeridge as a result of his intention to get his hands on Fairlie family money.
Mr. Fairlie, who usually has a pretentious and prejudiced view of the world, is not usually right in his assumptions. It is therefore ironic that he is right for once in his reading of a situation and character. Mr. Fairlie's hyperbolic laziness, hypochondria, and pretension offer comic relief at multiple points throughout the novel. This instance of dramatic irony has a similar effect, as it is funny that Mr. Fairlie would—accidentally—be so clear-sighted.
