Top Secret: ZooLu focuses on the blundering would-be evil villain Lulu Zielinski, aka ZooLu, as she attempts to create an evil plant-animal hybrid. But she fails miserably due to her lack of knowledge about basic plant biology. It's hard to create a new plant-animal hybrid if you don't know basic biology! Each book in the series focuses on a key STEM concept. Includes educational callouts, sidebars, and backmatter material. Supplemental activity also included.