"Revelatory to young audiences in more ways than one." --Kirkus "Many STEM-for-girls biographies fan excitement over women's achievements, but this title actually brings the central scientific concept within middle-grade reach." --The Bulletin of the Center for Children's Books Selected for the New York Public Library Best of 2019 List! Movie star by day, ace inventor at night: learn about the hidden life of actress Hedy Lamarr! To her adoring public, Hedy Lamarr was a glamorous movie star, widely considered the most beautiful woman in the world. But in private, she was something more: a brilliant inventor. And for many years only her closest friends knew her secret. Now Laurie Wallmark and Katy Wu, who collaborated on Sterling's critically acclaimed picture-book biography Grace Hopper: Queen of Computer Code, tell the inspiring story of how, during World War Two, Lamarr developed a groundbreaking communications system that still remains essential to the security of today's technology. Selected for the 2020 Outstanding Science Trade Books for Students K-12 list, compiled by the National Science Teachers Association (NSTA) and the Children's Book Council (CBC).