Get it here.
A real surprise. I expected Agatha Christie, and got P G Wodehouse with added death. Very funny in places, and written with the touch of an angel. And all the clues are there, if you want to solve the riddle yourself. But there is a lot going on besides the mystery, including a very post-modern series of references to the short-comings of detective fiction. There is some very out-of-date anti-semitism on show from some of the characters, which I hope dates the book, but other than that it is a fresh, interesting piece, with deeper themes which would reward deeper analysis. Sayers was a Dante scholar of renown, and a theologian also, so I doubt she wrote much without a purpose.