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.
Birdwatching tourists are ruffled when they spy the body of a landowner who had hidden the nesting site of the rare Red Crossbills from them. When the team unearths a ruby from a 25-year-old jewelry heist connected to the case, Rex tracks the birdsong to find the treasure at the secret nesting site, before the killer can get there first and destroy the endangered birds standing in his way.
