I really enjoyed the through-line of August and Rosalind working through their issues and past actions, and the twists did surprise me and logically followed the plot. The original conceit — Rosalind tricked into the governess position for her own son — was fun, and I laughed along with Rosalind at its uncanniness. 
However, this book was rushed. The second half had me breathless, because everything happened and resolved the way dominoes fall - faster and faster. I would’ve preferred if Armstrong had taken her time with the end. It would’ve been delicious, if drawn-out rather than crammed together. Still, Edmund was adorable and August had grown immensely from book one. I don’t know how I feel about Rosalind — I might have to think on it and return to this review when I form an opinion.