Double Agent

In June 1980, Rim Byeng-ho tries to defect to South Korea by crossing Checkpoint Charlie. He is shot and wounded by North Korean guards who try to stop his escape. South Korean agents retrieve him from no-man's land and congratulate him on his freedom.

A week after his defection attempt, Rim is subjected to brutal interrogation by South Korean Intelligence, who suspect he might be a spy despite his denials. The questioning takes place in South Korea, where Rim maintains his innocence. The process leaves him under serious scrutiny but not yet definitiva.

Senior leadership decides to recruit Rim after the North Korean files he brought are authenticated. Rim is to work for South Korean Intelligence, effectively becoming a double agent. This marks the start of his long undercover career.

In December 1982, Rim is posted to Gangwon province to help train South Korean spies who will infiltrate North Korea. During his downtime, he listens to Yun Su-mi's classical music radio program, contributing to his cover routine. The assignment expands his role beyond raw intelligence work.

Baek Seung-cheol arrives in Gangwon to inform Rim that he has been promoted and will return to Seoul as an analyst. The promotion signals a shift toward higher-level responsibilities within the intelligence apparatus. Rim contemplates the pressures of elevated trust from the organization.

By February 1983, Rim has begun to assimilate with his fellow agents and earns their trust, though he is kept away from highly sensitive materials. He continues to listen to Yun's radio program, which becomes a critical link in his cover and operations. The balance between belonging and exposure defines his daily routine.

The last musical piece on Yun's program serves as a coded signal, revealing its role in North Korean sleeper operations. Rim is to contact Yun, who has become a double agent, and their relationship begins to deepen under the cover of ordinary life. The dynamic complicates loyalties on both sides.

Rim passes intelligence about an upcoming mission to insert South Korean spies into North Korea via a fishing boat to Yun. Yun informs her own handler, 'Blue River', who is a doctor named Song Kyeong-man. The disclosure tightens the web of double agents surrounding Rim.

The fishing-boat insertion mission fails when the boat sinks and all men on board are presumed drowned. The failure triggers a scramble to recover intelligence and reassess sources working with Yun and Rim. The incident deepens the suspicions of both sides toward Rim.

Returning supplies to a hidden cache, Song and Yun are followed by an innkeeper who becomes suspicious and is killed by Song. The police are alerted, and Song is arrested and captured as part of the widening investigation into North Korean operatives.

Rim interrogates Song, the ranking North Korean agent in South Korea, who resists questioning. Rim beats Song into unconsciousness, and Song later attempts to kill himself, resulting in his hospitalization. The interrogation marks a turning point in Rim's credibility within SK Intelligence.

Baek becomes head of South Korean Intelligence and pledges harsher actions against radicals. Rim interrogates a student who had been to East Berlin; the student confesses to being a North Korean agent, but the coerced nature of the confession raises doubts about Rim's reliability and methods. The operation's control metrics come under scrutiny.

A North Korean agent questions Rim's commitment to the cause, while Yun begins to have second thoughts about their status as mere tools. It becomes clear that both are being used by their superiors, and their personal loyalties are increasingly at odds with the political agenda.

Yun is identified by Baek and must escape the country with help from Sean Howard, a British reporter. Rim retrieves secret documents from headquarters and hands them over to Howard, who then arranges Rim's escape to Nagasaki, Japan, and onward to another country. Rim realizes he cannot return to either North or South Korea.

In 1985, Rim and Yun reunite in Rio de Janeiro under new identities; Rim works as a fishing-boat crewman while Yun is pregnant. A Brazilian assassin shoots Rim as he stops to help a man with a broken-down car, and Yun waits for his return, left to face an uncertain future.