I really enjoyed Enola. The book is a first person narrative from her point of view. At the beginning she is scared and uncertain. However, she proves to have a brilliant mind capable of strategy and great deception. She learns a lot about life and human nature over the course of this one book and, because she is observant and processes information quickly, she is able to adjust herself accordingly and quickly. She is a girl who fights when she has to but mostly uses her wits to see her through. The book's supporting characters are also well written. Even the missing marquess, who is in the book very little, is given surprising depth (I really hope he shows up again in later volumes). I very much enjoyed the portrayal of Sherlock as well.
The first half of the book covers the mystery of Enola's missing mother and helps the reader to become acquainted with Enola and the world in which she lives. The other half of the book is more of an adventure story involving Enola's escape from the dooms of finishing school and her entanglement with the missing marquess. The whole thing is interesting, paced well and Enola's observations on life make for humorous and quick reading.
Nancy Springer did a wonderful job describing Victorian England. From the docks and slums of London's East End to the ridiculous practices of the upper class, this book has it covered. There is not a shiny gloss put over anything here. The prostitution, poverty and lawlessness of the East End are mentioned. There is an allusion in the prologue to the work of Jack the Ripper (the book takes place in 1888). The type of clothes women of the upper class had to wear and the restrictions put on girls of this time are well detailed. The popular view of women as witless and fragile is espoused by Sherlock and his brother several times. Enola's father was a rationalist and Darwin is mentioned as one of his favorite writers. Enola's mother is active in the struggling movement for women's suffrage. Pretty much every angle and aspect of Victorian society is given a nod to in this book and it is done without ever being didactic.
This book is marketed for middle grade readers but is enjoyable for any age. Teen and adult readers will enjoy it as well, especially if they like the mystery genre and are familiar with the character of Sherlock Holmes. Advanced younger readers will probably enjoy the mystery and adventure elements, but a lot of the rest of it will probably go over their heads. There are intense moments when Enola is held captive some younger readers might find scary.
I am very much looking forward to reading the other books in the series.