The Postman of the Apocalypse

In a post-apocalyptic world, Jeong-Guk Woo makes his living as a postman, all the while dreaming of the chance to ride the subway. When headquarters announces plans to revive it, Jeong-Guk is eager to take part—but government official Yong-Han Cho personally blacklists him, pointing out that his file contains no record of dangerous missions. Furious at being brushed aside, Jeong-Guk accepts a deadly assignment: delivering a letter to the AAA, a militarized zone infamous for refusing mail. Upon arrival, he learns the letter is addressed to Yong-Han's sisters, who plead with him to help them escape. Will Jeong-Guk stick to the postman's rules, or risk everything to help them?