The film is shot in black and white with the entire cast composed of local actors speaking their natural dialect.

"[3] Set during the Jeju Uprising on the island in 1948, O said the film does not focus on the large-scale struggle, but on a forgotten true story about a group of villagers who hid in a cave for 60 days to escape from a military attack.

[13] In November 1948, the U.S. military stationed in South Korea issues an order that all people living five kilometers outside the coast line of Jeju island are labelled as communist rebels and can be executed on sight.

[14][15][16][17] The events in Jiseul was triggered by the Jeju Uprising in April 1948, which began in response to police firing on a demonstration commemorating the Korean struggle against Japanese rule, morphed into an armed rebellion against the U.S.-backed military government in South Korea, and devolved into the republic's second biggest massacre that lasted until September 1954.

[citation needed] Until the late 1990s, mention of the incident, which reportedly destroyed more than two-thirds of the island's villages and killed 30,000 people, the vast number of them innocent civilians, was a criminal offense.