Kate Milford’s works weave elements of mystery, fantasy, and historical fiction, while also utilizing classic mystery tropes. Greenglass House is the first in a series of five books, all of which take place in the same fictional world of Nagspeake. Milford began building her fictional town when she wrote a draft entitled Wild Iron, which featured the Belowground Transit System and its conductor, Brandon, who appears in Greenglass House and the subsequent books. Milford states, “I’d spent seven years building the city of Nagspeake and I knew it intimately, and it wasn’t hard to start finding stories there” (Meythaler, Amy. “Kate Milford: Celebrating Success One Step at a Time.” Mackin Community, 25 Nov. 2019). Milford even created a website for her world called “The Nagspeake Board of Tourism and Culture,” which boasts all the historical and cultural attractions of the town. Influenced by her love of Agatha Christie, Neil Gaiman, and Ellen Raskin’s The Westing Game, Milford’s Greenglass books unfold with layers of intrigue and hidden motives as characters explore deeper issues such as identity, family, friendship, and heritage (Meythaler).

The first book in the series, Greenglass House was followed by Ghosts of Greenglass House in 2017, Bluecrowne in 2020, and The Thief Knot in 2021.