She’s been called the queen of horror, the mother of science fiction, and is one of the most recognized gothic novelists in literature. Mary Wollstonecraft Shelley, best known for the 1818 novel Frankenstein, or The Modern Prometheus — a totally terrifying tale that, nearly 200 years later, readers still turn to for a little spine-tingling reading — had a somewhat eerie life herself; and not just in the pages of her novel. Family scandal, an illicit love affair, travel, repeated loss, blackmail: all the stuff of a great novel or thriller, but for Shelley, these were the events of real life.

While literary legend has it that the original manuscript of Frankenstein was imagined and composed as part of a summertime horror story writing competition, the facts of Shelley’s life demonstrate that she’d had an affinity for the offbeat, eerie, and downright freaky from the very beginning. The novel has influenced popular culture for generations — from film and theater to other works of literature. (And yeah, in case you haven’t gotten the memo by now, Frankenstein is the doctor, not the monster.)

Here are 15 surprising — and totally freaky — facts about Mary Shelley, just in time to put you in a haunting, Halloween spirit.

Check out the entire What's Up, Boo? series and other videos on Facebook and the Bustle app across Apple TV, Roku, and Amazon Fire TV.

1 She comes from a legacy of feminist writing. Mary Wollstonecraft Shelley’s (then Mary Wollstonecraft Godwin’s) mother was the philosopher and feminist writer Mary Wollstonecraft — author of the 1792 title A Vindication of the Rights of Woman, one of the earliest published works of feminist philosophy. Shelley’s mother died less than a month after she was born.

2 She was the other woman. In 1814, then-teenaged Mary began a romance the poet Percy Bysshe Shelley, who was already married at the time. The couple conducted a two-year public affair and traveled throughout Europe — during which time Percy’s then-wife, Harriet, was pregnant. In 1816 Mary and Percy married, after Harriet’s suicide of Harriet.

3 Or… was it a suicide? There has been some speculation that Mary’s father, William Godwin, may have had Harriet Shelley killed in order to legitimize his daughter’s affair and then-pregnancy.

4 Her illicit courtship was a little… eerie, at times. Giphy Mary and Percy began meeting each other secretly at Mary Wollstonecraft's — Mary’s mother’s — grave at St. Pancras Church, in England. It seems the writer already had an affinity for the creepy before her classic novel.

5 She was familiar with death well before writing 'Frankenstein'. Sadly, Mary Shelley’s life was marked by death. In addition to suffering the death of her mother shortly after she was born, she also lost her half-sister Fanny to suicide, as well as losing three children in or shortly after childbirth. Percy’s first wife also died of suicide, and Percy himself died an untimely death just six years after they were married.

6 True to legend, 'Frankenstein' was written as part of a horror story writing challenge. During the summer of 1816 Mary — not yet married to Percy — wrote her novel near Lake Geneva, Switzerland, as part of a horror story writing game held between the poet Lord Byron, Percy Shelley, and a young physician named John William Polidori. Polidori’s own story from that long summer, "The Vampyre" was later considered the inspiration for Bram Stoker's novel, Dracula.

7 There may have been other inspirations as well. Despite legends, Mary Shelley maintained that the story of Frankenstein actually came to her in her sleep, as a dream. She may have also been inspired by Germany’s Frankenstein Castle, where alchemist Johann Conrad Dippel was said to have experimented on a human body he exhumed while living there.

8 Shelly was a young writer. When she began writing Frankenstein she was only 19-years-old, and she was 21 upon the book’s publication. It is widely considered the first science fiction novel.

9 Frankenstein wasn’t Mary Shelley’s only book. Though her best-known and clearly most widely-read book, Shelley also wrote the historical novels Valperga and The Fortunes of Perkin Warbeck, the apocalyptic novel The Last Man, the possibly-autobiographical novella Mathilda, two more novels, Lodore and Falkner, a small collection of travel writings, a number of short stories, several biographies of notable Italian, Spanish, Portuguese, and French figures, and more.

10 There was some early controversy over the authorship of 'Frankenstein'. Giphy First published anonymously in January of 1818, there was early skepticism about whether or not Mary Shelley was the primary author of Frankenstein. Stories about the extent to which Percy collaborated with her on the story vary, from Percy overseeing the majority of the writing to simply acting as an editor after the manuscript was completed.

11 She was considered a political radical. Following in the footsteps of her feminist mother and her political father, Mary Shelley was considered a political radical throughout her life — and her writings, including Frankenstein, have been analyzed for their feminist and communist themes, as well as anti-Catholic symbolism and resistance against individualistic societies.

12 Her husband drowned in a sailing accident. In a life already marked by death, Shelley suffered one more in 1822, when Percy drowned in a sailing accident, when his boat sank during a storm off the coast of Italy.

13 Legend has it that she kept her husband’s heart after he died. Portrait by Amelia Curran/Wikimedia Commons Though Percy was cremated, his heart was calcified and unable to be burnt with the rest of his remains. Shelley kept the heart, wrapped in one of her husband’s poems, in her desk, where it was discovered by her son after her death.

14 She was the victim of repeated blackmail. In the 1840s Mary Shelley was the subject of three separate blackmailing attempts, wherein she was threatened with exposure of her personal correspondence, letters between herself and Percy, and the publication of an unflattering biography of her late husband. Outside of purchasing some of her own correspondence back from the blackmailers herself, Shelley didn’t give in.