A classic of nineteenth century sf, where the story is told by an inhabitant of a two-dimensional universe who has become aware that a third dimension exists. As a teenager I had read Martin Gardner’s extended review of this book and similar writings, and to be honest it was better than the original source material, which is laden with assumptions about what the reader would find funny which rather grate on today’s sensitivities particularly with regard to gender but also class and race; it has not aged well. But at the same time the core message, challenging the reader to conceive of a conceptual breakthrough where our universe is just one aspect of a higher dimensional reality, is well executed – and of course the concept of other dimensions has become much more operational since 1884.

This came to the top of my TBR pile as the most popular sf book in my LibraryThing that I had not yet read. Next on that list is Walking on Glass, by Iain M. Banks.