Thursday Next is a LitraTec Special Operative. She looks after crimes related to literature. She is a Crimea War Veteran, this war has been going on for over a century. This is England, 1985.
Thursday gets a visit one day from an elite Special Operations person who is on the trail of a curious criminal who cannot be tracked. There is no evidence of his existence, no photograph, nothing through which he can be identified. He was Thursday's professor in college, hence, she is the only one who knows what he looks like.
Thursday sets off to help them but returns badly scarred when the criminal, Acheron Hades manages to do a lot of damage to her little unit. She is determined to track him down and returns to her home town, Swindon.
Her family is highly gifted. Her father is a rogue time traveler who pops back for mad little talks with her. Her uncle and aunt, Mycroft and Polly are highly gifted inventors of curious machinery which enemies are in need of. Mycroft has invented a Prose Portal that can take a user inside a literary work, or any book, in fact.
Acheron Hades uses the portal to kill off a minor character from Martin Chuzzlewit by Charles Dickens as a little reminder of what damage he can do to classical books. His plans are foiled by Mycroft and Thursday. Acheron Hades then sets his sights on a bigger classic, Jane Eyre.
Thursday is a very hands-on special operative, unlike her colleagues. They are content to sit behind their desks and do the literary work and let the other police do the field work. Not our Thursday, she MUST do everything, whether it is aiding Vampire hunters or stop a leak in time or hunting criminals on the streets.
She is a bit too hands-on and goes all over the place. Her fingers are in all the pies which is quite tiresome. The main part of the story, the part where Jane Eyre comes in, is at the fag end of the book.
That said, the book is a lovely read about an alternate universe where any changes made in the original manuscript affects all the books under print. It is a fantasy novel that makes ample allusions to classical books, which gladdens the heart of a die-hard reader of classical fiction like me.