The ending of this one really is interesting. And sort of confusing. The postscript clearly says that this is the final book in the series and will be followed by The Ashes of the Realm series. Wonderful. I always enjoy a good follow-up. However with the slightest bit of effort it is easy to see that there are at least three more books available. (You have to admit that putting 'Annihilation Series' in the title is what most would call A Clue.) The nice thing about this is that I have yet to find a dud in this author's catalogue and it is very easy to get caught up with what is happening so I doubt it truly makes much difference if you now go to the Ashes series or keep on with the 'new' Annihilation stories. Better yet, do both. You'll probably have plenty of fun either way.
Although this is a satisfactory conclusion to the series, I was left feeling a little disappointed. Too many loose ends were left untied and, although I can understand the desire to leave strings open for further series, you can have too much of a good thing! That said, there were some exciting moments and, even though Saxon Andrew tends to reinvent the wheel with the names of things, it was, despite the continuing grammar issues, a good read.