Fearing a third world war situation, CIA agent "Mac" Mackenzie recruits Ahab, the captain of an elite mercenary company named Black Lizard to infiltrate a secret underground bunker located 30 meters below the Korean DMZ and take out a target. However, it is soon revealed the target is King, the Supreme Leader of North Korea. Along with his team, Ahab attacks the forces surrounding King and takes everyone hostage. However, as they're about to leave after killing the hostages, Ahab's man is attacked and despite Logan's requests to wait and request for a medevac, Ahab is ordered to move. Arriving at his room, Ahab finds himself taken hostage by a teammate who offers him a better deal after shooting both Logan and King. However, Ahab manages to acquire a gun and kills him, and then proceeds to the bathroom where he thinks King to be dead. He manages to set up the whole contact system there. Mac makes it clear that everyone dies if King does the same. However, Ahab is found to be crippled with an artificial right leg. Its being broken limits him from movement, and he orders his men to search for the doctor who came along with King. Using a motion camera, he manages to locate Dr. Yoon Ji-eui and his fellow members. His men save them from being attacked, while Yoon instructs Ahab to bring back King's heartbeat back. He tells him to transfer O+ blood into King's body, but finds the blood pouch useless. He then calls a wounded Logan to the bathroom and after injecting him, starts transferring blood from his body to that of the King despite Logan's constant requests to not do so. Soon, the bunker is bombed, leaving Ahab and Yoon trapped, Logan dead and Ahab's army fighting the rivals.
Ahab and Yoon manage to contact each other and the latter helps him with extracting a bullet from his thigh. However, Ahab ends up tearing an artery, following which he tapes up his wound and instructs Yoon to find the blood pouches. In the meanwhile, Ahab finds network on his phone and receives a call from Mac. He asks for backup but is shocked to learn that she's been stripped off her charges and a second bombing has been ordered. He's told that while he and King would be rescued with President McGregor's support, his team and the North Korean doctor would be eliminated. Ahab leads Yoon to the room where he finds blood pouches but is stopped by an agent who's attacked by the former. With his team slowly dying, Ahab and Yoon remain the only survivors being hunted for. They manage to meet at the bathroom where Yoon transfers his own blood to King's body upon finding the blood pouches destroyed. Another gunfight ensues when the rivals enter the bathroom but are then shot by the backup team sent by Mac. President McGregor declares Ahab as a hero who fought to rescue King from the enemies, and eventually wins public support. Ahab, King and Yoon are rescued and taken in a plane which is soon attacked. An unconscious Yoon falls out of the plane and Ahab jumps with a parachute, first saving King and then Yoon by holding him tight as they swiftly reach the surface. Both Ahab and Yoon survive, and the latter gives him a shoulder as they begin walking.
