Chinese traditional magic, European fae magic, and the magic of other cultures exists alongside the non-magical world.
Elle is a descendant of a Chinese medicine god. She's got considerable magical talent, and was supposed to be a doctor.
Instead, she's working in a magical calligraphy shop, masquerading as a person of relatively modest power and careful to do nothing that would expose the truth, making magical glyphs for agents working for the agency that runs the magical side of this world. She has a regular client, Luc, whom she tells herself she regards as only a "business friend." It's just impossible for her to have any deeper feelings for him, because she can't risk exposing who she really is.