3.5 stars. While I'm still waiting for the perfect marriage of a military/spy book and paranormal romance/urban fantasy book, Once Bitten came closer than anything I've read so far.
The military aspect was on the lighter side and there was some weird quasi-romance or something going on between Jaz and Vayl that I never really figured out, but overall I enjoyed the book.
A few too many ends were left untied, but I'm assuming that's what the rest of the series is for. I liked it enough that I'm planning to read the second book.