Will Trent is undercover trying to get the goods on a master criminal called Big Whitey. His way in is through posing as an ex-con and making friends with low-life criminal Tony Dell. They both have jobs at the hospital.
Complicating things is Lena Adams, who is now a police officer in Macon, and is recovering from a recent botched raid to capture notorious killer and rapist Sid Waller, who also has possible ties to the elusive Big Whitey.
Will wants to keep his assignment secret from his girlfriend Sara Linton, because his case will inevitably lead him to become involved with Lena. Anyone who's familiar with Slaughter's novels will know that Sara holds Lena responsible for the death of her husband, Jeffrey Tolliver.
When Lena and her husband Jared Long are the victim of a shooting which leaves Jared - the son of Jeffrey - clinging to life, Will must figure out what happened during that raid that may have led to Lena and Jared becoming targets. He must also figure out if Big Whitey really is the head of a criminal organisation, or just an urban legend.
The fact that I am a long-time reader of Karin Slaughter's novels went a long way towards me forgiving the fact that is largely a dull, under-plotted thriller. Can we please move away from gangs and the like? Please? Please, please, please? It just doesn't generate the tension you would otherwise get if Will, Sara and company are tracking down a dangerous killer. Here, it's mostly just a hunt for the elusive head of a criminal organisation who has his hand in every criminal enterprise.
Another tiresome aspect is how Will hides this investigation from Sara because of Lena's involvement. Sara thinks that Lena is poison to everything she touches. Then we get Lena's point of view, where she comes across these days as fairly together and with-it. I began to get confused as to which side I was on. Did I side with Sara, who is ostensibly one of the main characters to feature in all of Slaughter's novels? Or did I side with Lena, who is clearly out of her depth in a situation in which she has no idea if she's somehow responsible for the mess that follows?
A lot of time in "Unseen" is spent on the relationships between the characters. And I mean a lot. Here, plot seems largely secondary. I've been a huge fan of Slaughter for over 10 years, so it was easier for me to overlook the many things wrong with this novel. If this was the first novel you read by Slaughter, you'd probably never read another book by her again. While there are one or two halfway decent twists, the plot is thin and not very compelling.
I'm hoping that "Unseen" signals a final move away from Lena and her legacy. A move away from Jeffrey Tolliver and his legacy. Start fresh with Will, Sara and Faith (who is underused here). Or if Lena has to be around, create something new for her to cause friction. Or just resolve it entirely. Lena seems to have her 'crap' together. Let's keep it that way. Let's hope that the next Slaughter offering has the tight plotting and taut suspense that we expect from her.