Classification, habitats, migration, hibernation, communication, and hunting across mammals, birds, reptiles, amphibians, fish, and insects. St. Francis of Assisi, St. Brendan, and St. Modomnoc anchor the Catholic thread. Twelve lessons.

How plants grow, reproduce, and defend themselves — from seed structure and photosynthesis to the strange strategies of carnivorous and parasitic plants. The parables of the sower and the mustard seed sit alongside the botany. Twelve lessons.

Mountains, caves, oceans, weather, climate, tectonic plates, the atmosphere, and the seasons. St. Damian of Molokai and St. Kateri Tekakwitha carry the stewardship theme. Twelve lessons.

The physics and biology of the sea: currents, tides, salinity, zones of light and pressure, and the creatures built for each depth. Twelve lessons.

The solar system, planets, moons, stars, and galaxies — with the order and scale of creation as the organising idea rather than an afterthought. Twelve lessons.

Ecology proper: populations, communities, food webs, biomes, adaptation, and biodiversity. Gregor Mendel, the Augustinian friar who founded genetics, belongs to this volume. Twelve lessons.

The cell as the unit of life — membranes, organelles, division, and the systems they build into. The smallest scale in the series, and the one that most provokes wonder. Twelve lessons.

Matter, elements, the periodic table, motion, energy, magnetism, and light — the laws that hold the rest of the series together. Twelve lessons.