Written by an accomplished fiction writer, Substitute: Going to School With a Thousand Kids is a fascinating documentary of American K-12 education, based on the author’s short-lived experience as a substitute teacher. He only taught for 28 days, so it would be easy to dismiss the experience as a gimmick, but his simple, factual narrative of each day shows, powerfully, the delights and horrors of school — and he very wisely refrains from offering a commentary, except for a very few instances. The 700+ pages draw a somewhat depressing picture. What is the wisdom of withholding recess time from misbehaving elementary school children? Why move along non-readers to middle schools? And why spend day after day filling out boring worksheets that focus on recalling scientific vocabulary rather than having the students reflect on processes? But there are also many portraits of good teachers, as proven by the habits and methods the substitute can glimpse, and Mr. Baker is a gifted teacher himself.