Geobukseon:
How does the novel end? I'm asking so I don't have to watch the final two episodes. (I don't care if the series is different.)
NOVEL SPOILERS AHEAD, OBVIOUSLY.
In the novel, the male lead makes a last stand against the kidnapper (the real BSE) and the mastermind. He publicly reveals that he is not the real BSE and that he knew that 406 was his wife: HHJ (HHJ thought that the male lead did not know that she was 406 before that point). Then an explosion occurs and, as far as the world knows, both the male lead and the real BSE are killed in the explosion. Park Do Jae goes to jail and he testifies against the people that he was manipulated into working with. I don't remember the exact details, but I presume certain complicit Baek family members were also sent to jail.
HHJ was distraught. Then she started to get phone calls from an international number beginning with 675. No one spoke on the other end of the line, but HHJ spoke and eventually she comes to suspect that the person calling her is the male lead. She eventually tracks him down to Argan (the novel's version of Afghanistan, where the male lead previously did military service and also worked as a war correspondent). HHJ and the male lead reconnect there and HHJ does some sign language interpretation for him with a deaf solider. They have a happy ending, complete with each of them saying a version of "I love you" for the first time and walking off into the sunset together.
The first side story (ironically, chapter 69) involves the two of them sleeping together for the first time, still in Argan.