While most of the novel focuses on the school and lessons, Sophronia and her new friends are also aware of a plot and a potential attack on the school for the prototype. The girls don't exactly know what it is, and in many ways it's more of a MacGuffin, simply something to add focus and an action, though I would have been happy just reading about Sophronia's day to day adventures at school. I expect I'll pick up the rest of Carriger's novel when I'm in the mood for something light and entertaining with some untraditional women.
Sophronia is the younger daughter in her family and a bit of a trouble maker. Her older sister is interested in all the proper feminine things but Sophronia is too curious and constantly gets herself into trouble. As a result, her mom decides to send her to boarding school but much to Sophronia's surprise, the school actually trains its students in espionage as well as traditional etiquette. Even though Sophronia lives in this steam punk setting, she has been very sheltered and mostly only heard about many of the things she encounters at school, including werewolves and vampires.