This is an OK read, better than many of its type if a little uneven, with a compelling ending and well named - the pace truly is relentless. Not even sure what genre this is. I had it as fantasy, but the opening chapters seem more like technological thriller, but after a while elements of fantasy start creeping back in. It's the first part of a trilogy, after all, and there's a prophecy... Anyway. Good, fast start, with an intriguing premise - man suddenly realises he's in a different body, and he can actually see his normal body across the street. What has happened to him and why is the central mystery of the book.
This is one of those books where the frenetic pace substitutes for depth, and neatly covers any cracks in the plot. Several times, I was thinking: hang on a minute, that can't be right... and then another man with a gun or a sword jumps out and off we go again. There's a lot of action here, and people getting hurt, and then having to go out into the action again and get hurt all over again. Anytime the action lets up for a moment, it's time for a mini-info-dump. And sometimes the scene jumps were a bit too abrupt, and I couldn't quite work out where we were or why or how they knew something or other.
The characters are a little unbelievable, and why is the hero's love interest is always so beautiful? But at least the author has made some effort to paint in the backstories of several of the characters and give them a little more depth than is usual. And the women are just as capable, feisty, aggressive and/or devious as the men. I found the hero just a bit irritating. One minute he's aggressively pursuing bad guys and demanding answers or else, the next he's reduced to jelly. But it is a strange situation he finds himself in, I suppose I can cut him some slack.
A number of people have categorised this as a Christian book. There's certainly no overt religious theme or characters, and the only unusual aspect is the small number of deaths for a book of this type. A great many get injured, sometimes repeatedly, sometimes badly, and some of them survive brushes with death an improbable number of times, but rarely is there an actual death. But those who are forced to kill agonise over it, there's a theme of forgiving even those who betray you and there's a recurring theme of good and evil, so perhaps it's right there without being preachy.
This is not at all bad, as such books go, although I never quite believed in it or got into that sucked-in page-turning mode. It's patchy - there are moments where it gets close to something more profound, and then it veers off into yet another car chase or racing down fire escapes or some such. I think the author visualises it as a high-action movie. The ending was rather good, with a number of very neat twists. Those with a greater ability to suspend disbelief, who don't mind the hero evading death by a whisker yet again or who enjoy high-action stuff with gun-fights AND sword-fights would probably like this a lot. Three stars.