October 1st, 2011 - mark that in your diary, Hal fans!
Yes, it's a junior series written for 9-12 year olds. Yes, adults are going to enjoy it anyway. The ebook version is under five bucks, and you can order a paperback edition from Amazon, Barnes & Noble, via my own website and any bookstore.
Publication details here, including ISBN
I'm Simon Haynes, programmer and author. Welcome to my website.