This is a gem of KBS special drama, very inventive, the drama grips you right the way through, just the right length for the story. My cyber mind being on high octane throughout, I was contemplating what the ending might be but the way you are kept guessing until the very final shot is awesome. The role of the father, though apparently a sideshow, turns out to be pivotal to the plot. I have to give this full marks overall, even the music was good. The only reason for the lower rewatch value is because this type of story hinges so much on the plot and once you know the ending it removes the drama that keeps you riveted (unless you are riveted by the actors anyway). If you like drama with a sci-fi twist, watch it.