It is, as one interviewee says, the ultimate “crime fighter by night” story. By day, Hedy Lamarr was the most glamorous star in Hollywood. By night, she was an inventor whose frequency-hopping technology is now used in bluetooth and wifi. This rousing documentary charts the story of a brilliant woman who was, in some ways, handicapped by her beauty. Film-maker Alexandra Dean explores a fascinating life full of contradictions. Lamarr claimed that the world never saw her true self, yet she lived her final years as a recluse, hidden even from her family. She was an immigrant who gave her all to support her adopted country but who was always regarded as an outsider.