Shiri

An elite North Korean unit endures a brutal training regime under Park Mu-young to become sleeper agents for infiltration into South Korea. The squad is tailored for covert operations, with Lee Bang-hee identified as the most promising sniper. The plan is to deploy them and reactivate the group at a later date to destabilize the South.

Over the next six years, Bang-hee carries out a string of high-profile assassinations against South Korean figures. Her missions cement her status as the primary threat among the sleeper agents. The operation remains hidden as the rest of the plot unfolds.

In September 1998, OP Center assigns Yu Jung-won to pursue Bang-hee. He is haunted by nightmares of her and is engaged to Myung-hyun, who symbolically gives him a pair of kissing gourami to emphasize loyalty. The personal stakes deepen as their security-clearance limits what Jung-won can reveal about his job.

An arms dealer claiming to have information on Bang-hee is shot dead by the assassin before he can reveal anything. The incident confirms that Bang-hee is actively seeking resources and perhaps catalysts for a larger attack. Investigators begin to see a pattern linking her to CTX.

CTX, a binary liquid explosive with a huge blast radius, is identified as the weapon at the center of the threat. Kim, a scientist at a lab connected to CTX, is assassinated by Bang-hee, signaling the plan to weaponize the chemical. The investigation links the liquid to the North-South sleeper operation.

Mu-young and his agents ambush a military convoy carrying CTX, killing the soldiers and seizing several liters of the explosive before authorities can warn them. The heist marks a turning point, showing the terrorists' commitment to unleashing the weapon. The stolen CTX raises the stakes for Jung-won and Jang-gil as they close in.

The initial CTX bomb is located atop a department store, but Mu-young misleads the bomb-disposal team about the deadline. As investigators pinpoint its location, the device detonates, causing numerous deaths and eroding public confidence in the authorities. The attack escalates the urgency to stop Bang-hee and the plot.

Jung-won takes Myung-hyun into hiding at a hotel as fear and strain from the pursuit mount. The stress triggers a relapse for Myung-hyun, who returns to alcohol, complicating the investigation and the couple's relationship. The personal and professional lines blur under the spiraling danger.

Jung-won suspects Jang-gil of being the leak feeding Bang-hee’s network, and both sides secretly bug each other’s equipment. Jung-won stages a trap by feigning new information, drawing Mu-young and his agents into a confrontation. The ensuing firefight causes civilian and police casualties.

When Mu-young is cornered, Bang-hee arrives to rescue him, tipping the balance of the exchange. The rescue unfolds amid gunfire and collapsing loyalties, revealing the depth of their collaboration. The moment deepens Jung-won’s pursuit and complicates the internal dynamics of the operation.

Mu-young makes a call to OP Center, demanding millions and a plane to escape, while revealing the CTX plan. Electronic surveillance devices in fish decor at the OP Center confirm Myung-hyun’s true role, exposing her as a key operative within the plot. Jang-gil confronts Myung-hyun in her shop, and Mu-young shoots him.

Jang-gil confronts Myung-hyun in her shop and is shot by Mu-young, leaving the investigation in a precarious state. Jung-won arrives with officers and a fierce firefight erupts as Mu-young and his agents attempt to flee. The confrontation thins the terrorist ranks but leaves the mission unresolved.

The terrorists target a stadium for a mass detonation during a North-South football match. They infiltrate the stadium, slipping in disguised as SWAT and security staff, and plant CTX devices around VIP zones. The lights are triggered to activate CTX as Jung-won and Sik coordinate a counter-assault, culminating in a lethal, high-stakes showdown where Myung-hyun is shot by Jung-won.

Jung-won discovers that Bang-hee was pregnant with his child and had left key details on his answering machine before heading to the stadium. He later visits the real Myung-hyun, who is undergoing chemotherapy, and she recalls Bang-hee with him. As a poignant memory song plays, Jung-won absorbs the losses and the cost of the mission.