Delay for Book Three - Explanation

I am afraid there may be a bit of a delay for book three.  Yesterday, I received a diagnosis of cancer.  It is serious enough that I am having surgery on Tuesday and I have no idea how long it will take me to get back to writing after that.  I had promised book three out by the end of the year but I am not sure I will be able to deliver.  It is still my intent and my goal, but health may decide I have to slow it down a bit.  Then again, mandatory time off work, may ba...