Search for the phrase hole in the wall and the results include a rock arch, a Norwegian country rock band, a Polish game show, and a British cash machine. This episode follows those four words through geography, culture, and everyday speech. The trail starts with literal gaps in rock, from a sea arch on South Africa’s Eastern Cape to a cave on Mount Cory in Alberta, and with the pass in Wyoming’s Bighorn Mountains that sheltered Wild West outlaws. That pass was no dead end. It was the narrow, easily watched front door to a secluded valley, a choke point no posse could approach unseen.

From there the phrase moved indoors, to a notoriously rough 19th century New York saloon and then to the modern compliment for an unpolished place with great food. The episode considers why a lack of polish now signals authenticity, and how artists have filled the same title with opposite meanings, from a 1921 silent film to bluegrass and industrial rock. It ends with the phrase at its most literal and its most hopeful: a wall with a cutout rushing at a game show contestant, and a computer set into a wall beside a New Delhi slum.

• Bela Fleck and the Flecktones released a track called Hole in the Wall in 1991. Two years later, in 1993, the German industrial band KMFDM used the same title on the album Angst.
• The game show began in Japan as a segment called Brain Wall, ran in the US from 2008 to 2012, and later inspired a popular Minecraft mini game.
• In British slang a hole in the wall is simply an ATM, named for the opening punched into a bank’s brickwork.
• In 1999 Dr. Sugata Mitra placed an internet computer in a wall facing a slum and walked away. Children taught themselves and one another to use it.
• The charity now known as SeriousFun Children’s Network, which runs camps for seriously ill children, was originally the Association of Hole in the Wall Camps.