Mary was a woman in historic London who discovered the book in a great library. Well, to be accurate her brother Harold had found it and given it to her- she knew of it through the records of the library she had found, but it was closed to women and she had to let him know where it could be found.
But in any case, now it was in her hands, and she knew just what she wanted to do with it. In her time, institutional sexism was far more blatant than today- women were excluded from so much of life as to be ridiculous. Despite educating herself with books and study, she could not vote, could not go to university, could not have many jobs men could, and generally was not taken seriously by much of society. Even her own parents thought Harold was the bright one, when in truth he merely collaborated with and listened to his sister, seeing her treatment as ludicrously unfair. (Part of why he supported her so much was because he was homosexual, and thus at risk of being subjected to even more unjust prejudice than her. In exchange for supporting his secret attraction to men, he supported her feminism.)
So, now Mary had the book, she had a great idea of what to do to fix the injustices of the world. She planned to...