3.5 stars instead of 4, because of the romance, which the book didn't sell me on at all: too one-sided, too insta-love, and overall too cheesy for me...(show spoiler)
On the other hand, Devi as a merc was a pretty badass, no-nonsense action girl who knows her shit and has survived so long because she's damn efficient. Cotter, too, was a character I liked: the resident jerk at first, but one who could've been just a stupid meatshield, and actually turned out to be a fairly decent person.
Though the world building was a bit on the light side, overall it made sense, and what was revealed about it seemed to fit as well. There were indications of psychic powers, too, brought in gradually, and I'd like to see where this is going to lead the series' general plot in that regard. (There must be a general plot, considering all the hints and happenings; it can't be otherwise.)
Odds of reading volume 2: fairly high