The main character is Harriet Vane a (wait for it...) writer of detective fiction and really terrific, strong, female character that's reticent to marry the handsome, charming, intelligent (filthy rich) Peter Whimsey because she fears he might not treat her as an equal (amongst other things).
Vane is asked to return to her alma mater, Oxford, where, in one of the women's colleges, a "poison pen" is wrecking havoc on the school. This "poison pen" writes vile things on the walls and sends people nasty and threatening notes. What's really interesting is how Sayers tells a rivoting mystery without that classic event of so many detective stories: a murder. In fact, she manages to tell the whole tale of the "poison pen" without ever actually writing any dirty words herself, leaving the reader is left to imagine what might have been written.
Written in 1936, the book displays a rather interesting pre-war sentiment. Here are two colloquial characters:
"When I was a lad," replied the foreman, "young ladies was young ladies. And young gentlement was young gentlemen. If you get my meaning."Like her other books, this one is very funny and awfully smart. I love the character of Harriet Vane, and look forward to reading the other books that are about her. She appears in Strong Poison and is also in Have his Carcase (?) and Busman's Honeymoon.
"Wot this country wants, "said Padgett, "Is a 'Itler."
This song comes up in the book, btw. Lovely. Also, thank goodness (and I don't think I'm ruining it) despite the fact that Whimsey is the famous detective, it's Harriet who is respected for her detective abilities and gets herself out of her own scrapes. Ultimately, Gaudy Night examines the sort of clash of pre-war England as people choose a cultural allegiance - progressivism and intellectualism or political and social regressivism (in a 1930s kind of way).
I would highly recommend this book - at 501 pages (paperback), you can really sink your teeth into it, and you'll want to!
Oh, brush up on your latin! And, if you have already read it and are a Harry Potter fan (or not...) check this out! Hilarious.