This is my 1st time watching a show w/ Jung Woo so I'm not sure about his acting. The story is interesting but…
Judging from the scars of the boys that were locked up, I think Kai is the older boy & Kang San is the little one. Maybe both were kidnaped for some experiment 27yrs ago & those rich guys had something to do w/ it? Lee Ha Naeul may be their mother?
This is my 1st time watching a show w/ Jung Woo so I'm not sure about his acting. The story is interesting but still annoyed by Dong Joo's over acting. Lee Sung Wook is always playing the weird creepy guy. This is my theory below