Acadia Greene has done science in summer, autumn, and winter. In the fourth and final book of this series, she carries her search for answers into the spring, investigating meteors and mass extinctions; germination and pollinators; parasites, ticks, and Lyme disease; and pesticides and malaria. Finally, looking back through her notebooks, she puts together her scientific inquiries from all four seasons into a holistic understanding of the natural world. Acadia is curious, determined, bold, and bright--a wonderful STEAM ambassador! Lexile 750