In 1375, China was in chaos between Yuan Dynasty and Ming Dynasty. Coryo (an ancient kingdom of Korea then) sent a delegation of many diplomats, soldiers and a silent slave to make peace with the new Chinese government. However, this delegation got charged as spies and sent in exile to a remote desert.
Princess Bu-yong

Park Jeong-hak
Ga-nam

Jeong Seok-yong
Ha-il

Lee Du-il
Ji-san