Detective Charlie Hudson teams up with what he calls his "highly trained law enforcement animal" German Shepherd dog named Rex who he prefers to team up with because he doesn't talk his ear off.
When a professional pet sitter is killed by a tree while looking after a tiny dog, Hudson and Rex take the case and discover everything from blackmail to a foot fetish.
When a controversial university professor is found dead in his classroom, Charlie and Rex investigate leads while Jesse goes undercover and soon finds himself danger.
When Donovan's ex, a recovering addict, wakes up with blood on her hands and a dead roommate in her apartment, the team moves quickly, finding there's more to the story.
When a deadly car accident leads Charlie and Rex to investigate reports of a mysterious blue light in the sky, they discover the truth is more science than fiction.