When the pharmacist at Charlie's aunt's retirement home is found dead, she alerts him to a mysterious string of recent fatalities among the home's residents.

Charlie investigates the host of a local morning show after her media mogul husband is suddenly found dead.

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

When an activist is killed during a break-and-enter at a water bottling plant, all evidence points towards his partner-in-crime, but Charlie and Rex aren't convinced.

Charlie and Rex reveal a conspiracy within the parkour community, after a thrill-seeker falls to his death.

Sarah finds herself in the middle of a hostage situation at a medical testing lab. When the team realizes there's no way inside without aggravating the gunman, Charlies sends Rex in to monitor the situation.

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.

With a gallery curator found murdered on his showroom floor and a missing sculpture, Charlie, Rex and Sarah are thrown into the world of high art. Jesse feels the burn when Sarah picks him as her new running buddy.

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.

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.

After a reviled restaurateur's food truck explodes, killing one of his employees, Charlie and Rex find themselves with a few too many suspects. A flirtation has Charlie torn between a possible new love interest and Rex, who makes no secret of his feelings on the matter.

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.

The animal lovers of St John's are under suspicion as Charlie and Rex investigate the death of a professional pet sitter. At home, Charlie finds himself in need of Sarah's help.