Sorry for the late update, but I actually have a reason. I got a job!!

I hate that this has to be so short.

At the end, they trick Ji ah by asking her a bunch of random questions to get her into a rhythm of telling the truth. Then they asked something important. Because she was in a rhythm, she almost answered truthfully. That slip up got her flustered, and the kidnappers were able to tell when she was lying. It's an interrogation technique I got from Criminal Minds.