A Modern Mephistopheles was written by Louisa May Alcott and published anonymously in 1877, when she was 25 years old, perhaps so she could explore a “darker side” without tainting her reputations. It was published under her name in 1889, along with her similarly dark story, A Whisper in the Dark. A mephistopheles is a demon from German folklore. A journal entry from February, 1877 explained what inspired her to write it: “It has been simmering ever since I read Faust last year.” You might enjoy getting more insights about her writing and life, in Louisa May Alcott: Her Life, Letters, and Journals.