Green is book zero of the Circle Series, being the beginning and the end of the series. Green focuses on Thomas Hunter, his family and the, relatively, small group of believers that gather in a future where spiritual reality has physical manifestation. To give more information may give away plot points, which is not my goal.
Being a huge fan of Ted Dekker and specifically the Circle Series, this book was an appropriate conclusion of the series and, ironically, a near perfect beginning. The story, occurring 10 years after White, is frustrating to people who've read the rest of the series, but that is a good thing. It brings out this emotion because you see what is happening and you want to scream at the characters.
Mr. Dekker, indeed, knows how to capture spiritual truth and create a compelling allegory that will blow the mind of any reader.
After reading Green, I'm now compelled to go back and read Black, Red, White and then Green again. Green, in light of the whole series, makes me hunger and thirst after the love of God all the more.
Ultimately, I would recommend Green to anyone who is a fan of The Lord of the Rings or Chronicles of Narnia, or anyone who is willing to learn through a singularly compelling allegory. I am one of those and I would give this book, and the entire series for that matter, 5 big stars and a high five to Mr. Dekker.