This movie is based on a true story called "the 7th Taechangho accident" that happened at South Korea, in 2001. A group of illegal immigrants from mainland China was tried to smuggled to Korea but 25 people were suffocated to death in the fish tank and dumped to the sea by the fisherman. Rest 35 people were set on foot to Korea and they disappeared until one was found, arrested and confess the whole event to authority.
Yun-seok Kim was first cast in the role of the ship's captain in June 2013. Joong-ki Song was originally offered to star opposite Kim, but had to turn down the role when he received his enlistment papers for mandatory military service. K-pop singer and actor Yoo-chun Park was cast instead in August 2013, in his big screen debut.