From a young age, Marie Tharp loved watching the world. She loved solving problems. And she loved pushing the limits of what girls and women were expected to do and be. In the mid-twentieth century, women were not welcome in the sciences, but Marie was tenacious. She got a job in a laboratory at Cambridge University, New York, but women weren't allowed on research ships. Marie dove deep into the data her colleagues recorded, slowly revealing a deep rift valley in the ocean floor.