Based on an unsolved murder case at a hamburger chain in Seoul?s multicultural Itaewon district in 1997, ?? opens with a graphically brutal scene in which an innocent college student is stabbed to death by a stranger. Two Korean-American teenagers, Pearson (Jang Geun-seok) and Alex (Sin Seung-hwan), are the prime suspects in custody, and each blames the other for the horrific crime. The suspects throw contradictory evidence at investigators, creating confusion about what actually happened, leaving prosecutor Park (Jeong Jin-yeong) to try to figure out the truth.