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. 

When a master painting instructor is pushed off a cliff, Mark and Rex scope out the art world to get to the bottom of a picture-perfect murder.