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.