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.

Hudson and Rex investigate the death of a parkour daredevil.

Charlie and Rex open a cold case that may be connected to a recent case; Donovan asks Charlie to spy on his daughter.

When a controversial university professor is found dead in his classroom, Charlie and Rex investigate leads while Jesse goes undercover and soon finds himself in danger.

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.

Hudson and Rex investigate a string of recent deaths at a retirement home.