The spy Im Su-myung refuses to speak. Kang Sin-jung is the lawyer appointed for Su-myung's defense. Sin-jung's interest is peaked. Su-myung was the youngest son of a ruined landowner. When two of his brothers defect to North Korea, the police torment the remaining family. In order to find out the truth about communism, Su-myung goes to the North too, leaving behind his other brother to watch over their mother. In North Korea, the three brothers are persecuted for being members of the Communist Party in South Korea.