Ha Chae-yoon (Son Ye-jin) is the top police negotiator who keeps a cool head in any situation. However, she spirals into shock when a hostage situation she responded to ends in disaster as she witnesses the hostages getting killed in front of her eyes. Just 10 days after the incident, Min Tae-goo (Hyun Bin), a notorious arms dealer wanted by the police, kidnaps a Korean reporter and police officer and picks Chae-yoon as the negotiator. Tae-goo creates an unprecedented hostage situation for unknown reasons and Chae-yoon cannot back down.