M-21 and M-24 kidnap Yuna and use her to call out Shinwoo so they can enjoy a fight between him and the Infected. Ik-Han informs Frankenstein about this, thus calling the wrath of both Frankenstein and Rai down on M-21 and M-24.
M-21 and M-24 kidnap Yuna to call out Shinwoo. M-21 tells them not to inform the police otherwise they will kill her. Shinwoo recklessly charges towards the location while Ik-Han informs Frankenstein about the situation. Frankenstein and Rai arrive at the scene, and Frankenstein releases his aura to call M-21 and M-24 for a battle. M-21 and M-24 decide to answer the call.
M-21 and M-24 are caught from behind. Frankenstein gives them the option to either die or leave silently. Unwilling to choose from the given options, M-21 and M-24 attack their unknown nemeses. M-24 battles Rai, while M-21 charges at Frankenstein using his speed and transformed claws, however, his opponent evades the attack effortlessly. M-21 acknowledges that his opponent is strong and hence asks M-24 for help as he thinks that he has killed his opponent. To his surprise, M-24's opponent is totally unharmed and M-24 is on his knees! This moment of distraction offends Frankenstein and he lands a powerful attack on M-21, damaging both his arms. M-21 wonders about the identity of his opponents and thinks he is dead when Frankenstein prepares to kill them. To his surprise, Frankenstein spares them when Rai orders him to do so. He asks them why they are leaving in a hurry, to which Frankenstein releases his aura and tells them they can attack again if they have the guts to do so. Frankenstein and Rai leave the scene after telling them to free the children.
Rai spares the lives of both M-21 and M-24 on the condition of them leaving the children alone. The fact that they let the children escape gives rise to major incidents in the future primarily because the Infected reveals the children's existence to Jake.