Gr 1–4—Growing up in Mexico, Mario Molina loved exploring the world around him and performing experiments with his microscope. After attending boarding school in Switzerland and receiving his PhD, Molina began work in the United States, where he made a horrific discovery: CFCs, chemicals used in countless everyday items, were damaging the environment by destroying the ozone layer. Despite Molina and his colleague F. Sherwood Rowland's attempts to publicize this discovery, they were not taken seriously until scientists discovered a huge hole in the ozone above Antarctica. Finally, Molina and Rowland's hard work led to almost every country agreeing to stop the production of CFCs. Vibrant, imaginative illustrations convey the possibilities of science and the urgency of Molina's discoveries and depict Molina's interest from an early age. Both English and Spanish texts flow smoothly. VERDICT An excellent addition to children's nonfiction collections, and sure to be a great highlight of Hispanic Heritage Month biography collections.—Selenia Paz, Harris County Public Library, Houston