This book is set in an alternate contemporary reality where shifters are fully out in society. "Therians" resulted from genetic mutations due to a virus and the anti-viral treatment of it. They are into their third generation of procreation and have governmental rights. The action takes place in NYC and THIRDS is the joint police force comprised of equal numbers of humans and Therians. 
 Dex Daley is a detective on the Human Police Force who has just testified against his human partner for killing a Therian in cold blood. The rest of the HPF is out for Dex's blood, and he's been beaten more than once before he gets a "promotion". Yep. Dex Daley's going to THIRDS, he's to be the replacement partner for Agent Sloane Brodie, a jaguar Therian with a seriously bad attitude. 
 Dex is a jokester, and uber-friendly human, always willing to reach out and charm the pants of anyone (mostly men) who he contacts. His boyfriend fled after the trial, and he's not feeling a lot of lot from the Destructive Delta crew to which he's been assigned. It helps that his adoptive brother, Cael, and adoptive father, Sgt Maddox, are on the Delta team, but Dex works his own magic inserting himself. See, all the Deltas were pretty broken up losing their teammate, Gabe, but Brodie took it worst because Gabe was his lover and he feels it a betrayal to accept any replacement for him. 
 Of course, Brodie also knows that if he refuses another partner he'll be reprimanded. So he makes life tough for Dex--who basically turns the tables time and again, working his hardest and proving himself. He's smart, and funny and charming and so unlike Gabe, but there's an attraction, one which makes Brodie furious. Dex does help Brodie blow off steam (read: smexytimes) and they engage in a down-low affair. 
 Meanwhile, several upstanding HumaniTherian supporters (people who fight for equal Therian rights) are killed, and all the evidence points to a jaguar Therian. Brodie is not under suspicion, per se, but he's not comfortable with all the scrutiny. He's faced a good deal of prejudice in the press and from humans--particularly from Gabe's brother Isaac. Isaac, for his part, seems interested in Dex, and wants to ruin Brodie--which leads to a whole plot arc regarding tolerance and prejudice. 
 In fact, the book is whole lot on cooperation and clashes within the Delta squad. Dex is finally accepted, but Brodie's not sure what to do with his feelings toward Dex--and he might not have a lot of time to figure it all out once the heat gets too hot searching for the murderer and the terrorists come out to play. 
 This is a fast-paced shifter M/M romance that has a lot of great characters and a well-planned story. Dex is hysterical--a perfect blend of whimsy and intelligence. His antics are well placed to diffuse the tension and also get his Delta squad to lighten up. He's a great match for the taciturn Brodie, who is so Type A I wondered if he arranged his sock drawer by color. Watching Dex melt Brodie's reserve was so fun. I really enjoyed this and will be reading the sequel.