The first book started the series out strong, and the second book added depth to a lot of characters, as well as introducing a few. The third book ties it all up well as well as adding to the Caterpillar Oracle's characters. I loved this book the best of all three, with the second one coming up... well, second! The first book stayed a little too long in London with "Alice", and that bored me a little bit, but when she comes back, it picks up fast.

You should create another series book, perhaps using something supernatural as a basis?