She played the neglected young wife of an indifferent older man.
The film became both celebrated and notorious for showing Lamarr's face in the throes of orgasm as well as close-up and brief nude scenes, a result of her being "duped" by the director and producer, who used high-power telephoto lenses.
She fell for his charming and fascinating personality, partly due to his immense financial wealth. She claimed she was kept a virtual prisoner in their castle home, and although like Hedy, his own father was Jewish, had ties to the Nazi regime of Germany, as well.
Her parents, both of Jewish descent, did not approve, due to Mandl's ties to Italian fascist leader Benito Mussolini, and later, German führer Adolf Hitler. Lamarr wrote that the dictators of both countries attended lavish parties at the Mandl home.
Trude, her mother, a pianist and Budapest native, had come from an upper-class Jewish family.
She had converted to Catholicism and was described as a "practicing Christian" who raised her daughter as a Christian.
Throughout Europe, it was regarded an artistic work.
The film was put on hold, and Lamarr was put into Lady of the Tropics (1939), where she played a mixed-race seductress in Saigon opposite Robert Taylor. Stewart was also in Ziegfeld Girl (1941), where Lamarr, Judy Garland and Lana Turner played aspiring showgirls - a big success. It was successful at the box office, as was Crossroads (1942) with William Powell.
Lamarr played the seductive native girl Tondelayo in White Cargo (1942), top billed over Walter Pidgeon. White Cargo contains arguably her most memorable film quote, delivered with provocative invitation: "I am Tondelayo. " This line typifies many of Lamarr's roles, which emphasized her beauty and sensuality while giving her relatively few lines. She reportedly took up inventing to relieve her boredom.
Lamarr accompanied Mandl to business meetings, where he conferred with scientists and other professionals involved in military technology.
These conferences were her introduction to the field of applied science and nurtured her latent talent in science.