In 1989, a 22-year-old South Korean student caused an uproar when she sneaked into North Korea and was filmed advocating for unification and meeting leader Kim Il Sung.
The unauthorized visit was orchestrated by Im Jong-seok, a prominent student democracy activist who is now chief of staff of South Korean President Moon Jae-in.
Nearly 30 years on, the 51-year-old Im is now playing a pivotal role in an inter-Korean detente fostered by the Winter Games in Pyeongchang, officials and experts say.