A Spy in the House (Agency #1) by Y.S. Lee

Historical Mystery YA

Rescued from the gallows in 1850s London, young orphan (and thief) Mary Quinn is surprised to be offered a singular education, instruction in fine manners — and an unusual vocation. Miss Scrimshaw’s Academy for Girls is a cover for an all-female investigative unit called The Agency, and at seventeen, Mary is about to put her training to the test. Assuming the guise of a lady’s companion, she must infiltrate a rich merchant’s home in hopes of tracing his missing cargo ships. But the household is full of dangerous deceptions, and there is no one to trust — or is there? Packed with action and suspense, banter and romance, and evoking the gritty backstreets of Victorian London, this breezy mystery debuts a daring young detective who lives by her wits while uncovering secrets — including those of her own past.

1850s London smelled terrible. To be more accurate, the Thames in 1850s London had such an unpleasant stench of rotting bodies/food/God knows what else that it stunk up the surrounding city. Victorian London has never been so unglamorous. 

Mary Quinn is an equally unglamorous heroine. She cares not one whit about current fashion, etiquette, or embroidery. She's tough, intelligent, acutely aware of the limited roles available to women, and of vulnerable women can be in such a cruel city. Which makes it all the more interesting when she's plopped into a genteel house, where it's necessary she pretend to be a placid, Bible-reading companion. 

She quickly crosses paths with her "love interest," an intrepid James Easton. The scenes between the two are playful and delightful, and I especially love how she has to save him in the end! 

Mary's deep, dark secret may have come as a surprise to some, but I had already guessed it way before the reveal. That said, I think it gives the novel a compelling, satisfying complexity. Identity is a difficult thing to grapple with in the best of times. Mary's own struggle reveals so much about the Victorian era and sensibilities. 

There are two more books in this series, and I plan on reading both of them. Mary was a great protagonist, and I'm very interested to see whether she will run into James again.