The titular baby is building a tower with blocks, and Spiro uses this as an example to show how everything in nature, and the universe, is built by quarks, molecules, etc., even baby. The earth-hued illustrations show cute little balls as the quarks which gather together to create all the things in the universe. The story ends with scientists smashing an atom and baby smashing a block tower.
I felt that this concept was too complex for a board book. It showed the atoms and molecules forming things like oxygen, methane, and water but I don't think kids will understand the idea of gases.
Verdict: This was fun, but the concept doesn't work well for the audience and format. If you're buying the whole series go ahead and add it, but it's not a priority.
ISBN: 9781580895408; Published 2016 by Charlesbridge; Review copy provided by the publisher for Cybils; Donated to the library