Well, if you liked the first two Jon Shannow books, you'll enjoy this one, too. This is the final book of the Stones of Power series and to get the most out of it, you really need to read "Wolf in Shadow" and "The Last Guardian" first; unless you're the type of person who watches Return of the King before seeing the other two Lord of the Rings movies.
The story focuses a bit more on the supporting characters and there is more dimensional / time travel in this book. The book is about half Jon Shannow and half all of the other surviving characters in the series. It's pretty interesting to read because the side characters are well written and they can get killed off at any time. So, when there is danger, nobody is safe. The story was a bit harder to follow because it does skip around a bit more than the last two books, so you really need to pay attention. As in all other Gemmell books, the good guys are real people and there are plenty of bad guys to kill.
Jon Shannow returns as a gunslinging preacher who struggles to do what is right, but is put into situations where he must kill evil men for the greater good. As a man, he has many flaws, but he never lies. Men who have inner strength never need to tell lies.
The supporting cast is a good mix of young and old folks from westerns. They've all got courage and strong willed personalities. They are less interesting than Jon Shannow, but you still manage to care for them. When the bullets start flying, they don't all make it.
The bad guys are fairly one-dimensional, but they're controlled by the Bloodstone. A source of power that strengthens men, but fuels their inner rage.
David Gemmell can paint a beautiful heroic picture with just a few words. His characters are memorable because their motivations are clear and they fight for what they believe is just. There are also lessons about what it takes to be a good person, a great man, a strong man, or a weak man. David Gemmell never beats you over the head with this stuff. It's usually told in action accompanied by a few sentences that makes you see the world differently. After reading many of his books, I have a new appreciation for nature and people with inner strength.
This book is loaded with old west style action. There are gun fights all over the place and there are consequences. There are shootouts, werewolves, cavalry, sieges, a bit of magic... And the action is suspenseful and exciting.
This is like an R Rated action film. Nothing is graphic and there's no sex, but there is a high body count.
This is a good book. Although the story lacks momentum because it focuses on the lesser characters and skips around a bit, there are some inspirational scenes in this book that really make you think about the world. And of course, the book is loaded with action. If you enjoyed the first two books, then you should enjoy this one as well. Just be warned that the supporting characters take center stage quite a bit and that you do need to pay attention to the plot.
Buy this book if you enjoyed the other two.
Buy the other two if you like David Gemmell's heroic writing style and westerns.
Avoid this book if you don't want to read a western.
Avoid this book if you don't like time travel and a mix of the old west with modern day tech.
If you enjoyed the Jon Shannow Books, keep reading David Gemmell's work. Most of his books are medieval fantasy, but they're great. I'd recommend Legend, Sword in the Storm, Waylander, Winter Warriors, and The Lion of Macedon for starters.