The Annotated Flatland, Adwin A. Abbott & Ian Stewart
Flatland the tale of an individual, a square, living in a two dimensional world. He has a vision of a one dimensional world and is then introduced to the misterys of the third dimenision by a strange spherical visitor. This is all an excuse to get the reader to think about the fourth spatial dimension. In this edition many annotation with additional information have been added. If you're confused or interested by this then you might want to have a read.
