Four is the magic number in Michael Martone’s Four for a Quarter. In subject — four fifth Beatles, four tie knots, four retellings of the first Xerox, even the sex lives of the Fantastic Four — and in structure — the book is separated into four sections, with each section further divided into four chapterettes—Four for a Quarter returns again and again to its originating number, making chaos comprehensible and mystery out of the most ordinary.