The Suspect tells about the character Dong Chul – a famous former agent of North Korean. After giving up working for the company, he lived with his family, spent time on caring his wife and children. But unfortunately, in a political move, his wife and his children were missing.
A spark of mutual interest is ignited between the man and woman at the gathering point of this special camp. The duo then falls in a forbidden love in Finland covered with snow.
The film follows a man (Gong Yoo), his estranged daughter and other passengers as they fight their way through a countrywide viral outbreak on a suspense-filled, blood-drenched bullet train ride to Busan.