Tati Gabrielle is slated to return to "You" as librarian Marienne Bellamy, who's moved to Paris to escape Joe! Marienne was Joe's season three obsession, and the season ended with him travelling to Paris to search for her.
Apart from "You," you know the 26-year-old California native from "Chilling Adventures of Sabrina," "The 100," and "Uncharted".