On 31 January 1968, 31 North Korean commandos infiltrated South Korea in a failed mission to assassinate President Park Chung-hee. In revenge, the South Korean military assembled a team of 31 criminals on the island of Silmido to kill Kim Il-sung for a suicide mission to redeem their honor, but was cancelled, leaving them frustrated. It is loosely based on a military uprising in the 1970s.

Cho-won is an autistic but happy young man who loves to draw zebras and run. His mother wants him to feel normal by accomplishing a feat that no one thought his son could achieve. With the help of a coach in exile, she trains him to become a marathon runner.

Hyeon Dae and Min Joo thought one of them getting married would end the sex-partner relationship. However, they can't hold in their desires and Hyeon Dae destroys himself with sex, while Min Joo can't give up what she can't have. At the same time, they have a complicated and ugly relationship with past characters.

So-eun, who was born in Seoul but especially loved Gang-neung, joins the Gang-neung Cultural Foundation after graduating from university.

The President of South Korea races against time to prove the seal on documents from long dead King Gojong is fake by charging outspoken historian Choi Min-jae, and a descendant of the royal bloodline Kim Yu-shik, to find the long lost seal in order to prove that the Japanese claim to railroads is false, a claim that will stop the reunification of the two Koreas.