When homicide detective Dexter J. Daley's testimony helps send his partner away for murder, the consequences - and the media frenzy - aren't far behind. He soon finds himself sans boyfriend, sans friends, and, after an unpleasant encounter in a parking garage after the trial, he's lucky he doesn't find himself sans teeth. Dex fears he'll get transferred from the Human Police Force's Sixth Precinct, or worse, get dismissed. Instead, his adoptive father - a sergeant at the Therian-Human Intelligence Recon Defense Squadron otherwise known as the THIRDS - pulls a few strings, and Dex gets recruited as a Defense Agent.
Dex is determined to get his life back on track and eager to get started in his new job. But his first meeting with Team Leader Sloane Brodie, who also happens to be his new jaguar Therian partner, turns disastrous. When the team is called to investigate the murders of three HumaniTherian activists, it soon becomes clear to Dex that getting his partner and the rest of the tightknit team to accept him will be a lot harder than catching the killer - and every bit as dangerous.