Young Fidelia Knight arrives in Melbourne in 1874, alone except for her treasured companion, Samuel Johnson; well, half of him. To escape servitude, Fidelia hides each night in Bourke-street's renowned Coles Book Arcade. She loves words, you see, and wants to know them all. What she overhears in Coles sets her on a path that will change the lives of everyone she meets, starting with Jasper Godwin, the hopelessly underqualified manager of the new Billings Better Bookstore. Fidelia's thirst for knowledge is contagious. She tutors two orphan boys and two illiterate women, inspiring them to unlock their creativity; and her exploration of colonial Melbourne takes her to some unusual places. Nothing daunts this diminutive genius, except the mystery of what really happened to her parents on the voyage from England.