Silmido is a 2003 South Korean action drama film directed by Kang Woo-suk. It is based on the 1999 novel Silmido by Baek Dong-ho, which in turn is based on the true story of Unit 684. Some parts of the film are dramatizations, as the actual details of certain events remain unknown. The film was both critically well-received and financially successful and was the first film in South Korea to attract a box office audience of over 10 million viewers.
On 21 January 1968, 31 North Korean commandos of Unit 124 are shown to have infiltrated South Korea in a failed mission to assassinate President Park Chung-hee.
As a means of retaliation, the Republic of Korea Armed Forces assembled a team of 31 social outcasts including criminals on death row and life imprisonment, in a plot to kill Kim Il-sung. The team is designated 'Unit 684'. The recruits are taken to the island of Silmido for training. The mission is offered to the recruits as the only way to redeem themselves and show their loyalty to their country. If they succeed, they will win their freedom and a new life. With this goal in mind, they endure their training. The training is shown over several months, with the recruits enduring various forms of extremely vigorous training and regular physical punishment, including being branded. One recruit is killed after he falls from a ropes course.
At the end of their training, they are dispatched on their mission to North Korea but are recalled not long after their departure. It is revealed that the project has been called off, as the government attempts a peaceful reconciliation with the North. The recruits return to Silmido discouraged and frustrated. Shortly afterward two of the Unit 684 members escape from their barracks and rape a female doctor. They are quickly discovered and believing that they will be executed, decide to commit suicide. One kills the other at his request but is apprehended before he can kill himself. The apprehended soldier is then returned to the camp, tied up, and made to watch his fellow Unit 684 members being beaten by the guards for the two men's betrayal. Enraged, one of the Unit 684 members being beaten can take his guard's bat and kills the tied-up soldier for bringing disgrace to the unit.