Zero Sum Game kicks off with our hero, Cas Russell, in extreme jeopardy. In many ways, jeopardy seems like a place that Russell returns to again and again and again. Russell is a retrieval specialist, not a detective, but when she was sent to retrieve a young woman from some nasty people, she steps into a huge conspiracy with worldwide implications, an organization called Pithica. There’s also an anti-Pithica which may or may not be a rogue government agency.

Russell is not your usual hero. She’s good at math, very good. Good enough to calculate the equations and trajectories of a gunfight faster than a speeding bullet. Well, not quite, but close enough. This gives her the ability to seem almost superhuman, knowing exactly how to leverage momentum and angles and force to seem to climb walls, for example. It’s quite disconcerting to Arthur, the real detective she encounters, an antagonist who becomes an ally. Other characters on her side are the psychopath Rio whose brutal psychopathy has one exception, a loyalty to Russell that is inexplicable to her, too, but strong enough for her to trust it absolutely. There’s also Checker, a computer maven, who is the only one who can actually grasp how smart Russell is.

I enjoyed Zero Sum Game though I did have to suspend disbelief from beginning to end. After all, it’s not just math. Lots of mathematicians can calculate vectors without being able to use them to take out a dozen bad guys. Then there is the worldwide conspiracy with Pithica that makes this more speculative fiction than most thrillers. This presents a moral dilemma for Arthur, Checker, and Cas. This seemed the weakest part of the story. I guess I am less of a relativist and would have no qualms with their choice.

I am pleased to learn that this is a re-release which assures me that there are two more books in this series that I won’t have to wait years for the author to write.

I received an ARC of Zero Sum Game  from the publisher through a Shelf Awareness drawing.