Catherine has had very limited experience of the world, in a good family, good neighborhood, with little variation in company.

She's suddenly exposed in Bath to a wide variety of people, the most apparently attractive of whom turn out to be nasty specimens of humanity. Her experience declines gradually into dismay except for the redeeming influence of Henry and Eleanor.

Now she sees yet other apparently pleasant members of her new experience turn out to be pretty nasty specimens; and her active imagination conspires with her inexperience to make a truly dark environment lead her astray.