Well, that is also the plot of the book; the Classics department is, basically, the Fairy Court, with the head of department as Fairy Queen, and Thomas Lane is the student who Janet falls in love with and has to save from her clutches. However, there is a very low ratio of plot to atmosphere so there's much more to say about the atmosphere, and most of the plot is concentrated at the end of the book so it's quite hard to mention it without being spoilery.