The Suspect — Ending Explained

Dong-cheol's taxi-driver life is a cover. He is a former elite North Korean agent who was abandoned by his own side on a mission, and his wife and daughter were murdered by his former comrade Ri Kwang-jo. When he witnesses the murder of his employer Park Geon-ho, the killing turns out to be the work of a death squad tied to NIS chief Kim Seok-ho. Kim frames Dong-cheol and turns the state's manhunt into a cover-up.

As Colonel Min's pursuit tightens and the documentary producer is drawn in, the climax brings together Kim's corruption, Dong-cheol's revenge and the exposure of the truth. The key point that only becomes clear in hindsight is that the "suspect" of the title is the one innocent party, while the real criminals sit at the top of the security establishment.

The searches did not provide a verified, detailed account of the final scenes, so the exact resolution is not described here.

As pure genre spectacle: some critics treat the film as a fairly typical action vehicle, with a predictable story that mainly exists to set up chases and fights.

As political allegory: another reading sees Dong-cheol's framing as a critique of South Korea's intelligence apparatus and of how defectors are used and thrown away by both states.

As a character study of grief: because the film has so little dialogue, some viewers read it mainly as Gong Yoo's silent portrait of a broken man, with the action working as an expression of his loss.