Whose Body, with Lord Peter Wimsey as the amateur detective, was Dorothy Sayers first novel, published in 1923. While it is as enjoyable today as it was back in the 1920s, many of the references Sayers makes throughout the book aren't immediately clear to today's readers - especially those in the United States.
For example, at one point Wimsey says to his mother, "You're a brick." He means it as a compliment. Why? Well, way back in ancient Greece, King Lycurgus of Sparta was asked why there were no defensive walls around his city. 'There are Sparta's walls,' he replied, pointing at his soldiers, 'and every man is a brick.'"
Increase your enjoyment of Whose Body? 100-fold with this annotated edition. The annotations are placed right in the text, bolded, so that it's easy to pass over them if you're not interested in a particular entry.
Then, when you've finished the annotated edition, the book is repeated again, with no annotations, so it can be read simply. Two books for the price of one!