*Minor, very minor spoilers ahead*
I'm glad I stuck with the series, I didn't care for the first book, I despised Melody, and Jane was irritating. The second book was better, and this third one is definitely the best in the series so far.
Melody has completely redeemed herself, I would probably read a book with her as the main character.
At times, Jane still irritated me, at those times her actions were mainly to move the plot along, even though I didn't feel that they were true to her character - the whole scene at the oculists, seems implausible with Jane's character, and how highly she prides herself on hiding her true emotions and behaving well publicly. I'm sure the intent was to show how deeply distressed Jane was at the time - but it felt more like she was channelling Mrs. Ellsworth, then acting as herself.
Otherwise, I loved the intrigue in this one. Very well done! I wasn't sure how they were going to come through in the end.