Marcus Absolutely, you won't be missing out on much story-wise, but I would definitely recommend reading the first two too as they are really good!
Race Bannon I disagree with the other answers. There are several chapters toward the end of the book that sum up the "essence" of the first book "The Hypnotist". You would be doing yourself a disservice if you read this novel in its entirety without having read the first one. Just my opinion.
Maggie I was able to get the first 3 at my local library (Ohio has a state network for library books). The fourth one is there too, but the audiobook is not- which is what I need. Love this series! But the 3rd one leaves me wanting more.