I'm going to have to be honest with this one. I didn't love it. Perhaps I came in upon the UF bandwagon too early or too late, and while I think it's a fairly polished and frankly never ending tale (which I do like, on occasion,) but it just comes across as more secret service urban fantasy schtick. No amount of amnesia gimmicking or clever info-dumps will disguise it for what it is, and I was saddened by the lack of underlying, grab you by the balls, tension. 
 It did pull off a very well-done piecemeal of episodic tv-like modern fantasy, though, and I'm sure I'd have really enjoyed it if it was a prime-time CW hit, but the fact is, a 31 year old amnesiac shouldn't actually read as a YA protagonist. I like YA when its centered around an actual youth. There are only a mere handful of protagonists that I can accept as the exception to this rule, such as Herne's Iron Druid, who happens to be a few millennia old, but I'm afraid Ms. Thomas has none of the required personality traits to pull that off. 
 I will say that I do appreciate the long plot, new developments, and above-average enemies, but I am completely spoiled by the whole chess plot after reading Dan Simmon's Carrion Comfort. This novel just can't compare. But that isn't to say this novel doesn't have a lot of excellent points. 
 It is very readable. A lot happens. It's full of action and revelation. It ought to be the primary focus for anyone just now getting into the YA/UF scene. It packs an awful lot of story in such a small package. 
 Unfortunately for me, I never quite connected with the MC. I didn't really care about this secret English agency. I never really got the sense of urgency, despite all the calls out into the field, the underlying terror of the grafters, or whatnot. But because this novel was well above the average crap that is out there, I still appreciate it for what it is, and I'll support and read its sequels to come. I've read a LOT worse. 
 Until then, it was a pretty fun ride! (But to put things into a bit of recent perspective, the movie Kingsman was much more enjoyable, even if it didn't have psychic fungus.)