A Mathematics professor develops a theory of "intra-dimensional" spaces, hypothesizing that the vast, empty spaces in atoms form a parallel dimension in which alternative histories of "what might have been" have real existence. He ends up becoming a carpenter who builds mathematically precise staircases to access these worlds (!!! one smiles at the simplicity of transforming theorems into ladders; sort of like Erdos' mathematician in reverse, who converts coffee into theorems). There isn't much Math content as such beyond this flimsy quasi-explanation for an otherwise tall-tale; it does have the charm of the old-time tales, though short on plot.

This was the first book I ever bought in my life, in a far away country, at age 12, with my very own money, on my very own way to school, out of a window bookstore. Today, as a professional mathematician, I am certain this book was one of the many influences toward this direction. I don't have the book anymore, of course. I am constantly looking at online stores to buy it again, to re-read it again!