It’s never easy being ahead of your time. This was especially the case with the mother-daughter team of the pioneering eighteenth-century feminist Mary Wollstonecraft and Frankenstein author Mary Shelley. Both were independent, intellectual figures at a time when those traits were not valued in women. In both cases this led to them being social outcasts. Even though Mary Shelley — she took the name of the flighty poet she married — never knew her mother (who died only days after giving birth to her), the fruit didn’t fall from the tree. This was not an unconscious coupling. As her daughter put it in the language of the day, her mother’s “greatness of soul perpetually reminded me that I ought to degenerate as little as I could from those from whom I derived my being.” She should have degenerated more, for her own good, given a weakness shared with her mother for less than ideal men. Of these, one of the most damaging was William Godwin, Wollstonecraft’s husband and Shelley’s father, a selfish pedant who must have been hard to love at the best of times. Charlotte Gordon’s dual biography of the two Marys is written in alternating chapters to help draw out parallels like these, and tells the story of their dramatic lives, so full of ground-breaking creative achievement and tangled family dynamics, in a direct, captivating manner.