Jackie goes undercover as an escort when she and Danny track down a serial killer who is murdering prostitutes in hotel rooms. Meanwhile, Erin meets a potential suitor at an art gallery who shares her interests.

The station is abuzz as Nick and Hank are called to a case where an innocent flash mob results in a gruesome homicide. As Nick delves further into the investigation, he learns more about his unique family history, and finds himself at odds when he and Hank are assigned to protect a dark character from his recent past.

Dave welcomes actor Steve Martin and actress Felicity Jones.

From Alameda to Africa, from the desert to the deep blue sea, the MythBusters declassify their top destinations and reveal all kinds of inside scoop, from quarry-bans to unplanned myth busts.

Stephen Fry asks some taxing questions about things that start with I, with Sandi Toksvig, Al Murray, Dara O'Briain and Alan Davies.

While on a hunt, Sam runs into someone from his past and a confrontation ensues. Meanwhile, Dean reluctantly teams up with a quirky, laid-back hunter named Garth, when he finds himself in a situation that he just cannot explain.

Guest stars Drew Carey and Linda Cunningham. Geoff Peterson voiced by Louie Anderson.