The title of episode 65 (of 82) is an abbreviation for Date Of Conception and it centers around the pregnant Sun. Did she conceive the baby off island with her extramarital lover or did she conceive on island with the previously sterile husband Jin. Juliet on the spot sees another chance to help out and volunteers to do an ultrasound to find out just when Sun’s baby was conceived.
The off island flashback concerns Sun being blackmailed by a woman or she will reveal something that will cause Jin great shame. He has told Sun that his parents are dead, but she manages to track down his father, a poor fisherman from a remote village (pictured above, who looks like he has a hell of a dental plan) and will that might seem shameful, what the father reveals is even worse, his mother “had been with many men.” She of course pays off he blackmailer who it turns out is Jin’s mother.