"D.O.C." is the 18th episode of the 3rd season of Lost and the 67th episode overall. It was aired on April 25, 2007. The episode was written by Edward Kitsis and Adam Horowitz and directed by Fred Toye. The character of Sun-Hwa Kwon is featured in the episode's flashbacks. The title is a reference to the medical phrase of the same name which stands for "date of conception", referring to the episode's plot of discovering Sun's D.O.C.
Plot
Flashbacks
In flashbacks, we see Sun in a park. A middle-aged woman sitting next to her points out Sun's wedding photograph with Jin-Soo Kwon in the newspaper and inquires if that's her. Sun affirms that it is. The woman suggests that it would be embarrassing if the world were to find out that a daughter from the wealthy Paik family had married a man whose mother is a prostitute. The woman demands money as blackmail. Later, Sun asks her husband about his family. He tells her that his mother died when he was a child, then gives conflicting stories on when his father died. When she pushes for more information, he grows angry and asks her to drop the issue. Sun visits Jin's father without his knowledge, who confirms the woman's story. He never told Jin his mother was a prostitute and is still alive, and pleads with Sun not to tell his son the truth. He also mentions that he raised Jin alone and is not even sure he is his biological father. Sun then visits her father and asks for the money. When he demands a reason, she tells him that she has never pried into his affairs, which are clearly illegal, and would like the same respect. However, she admits that the money will prevent great shame coming to someone she loves. Mr. Paik realizes she means Jin, and tells her that he will bear the debt by working for him directly, instead of as a floor manager. Jin discovers the money in Sun's purse. She concedes she got it from her father, but claims it was just for furniture and their honeymoon. Jin says he doesn't want to be any further in her father's debt, and asks her to return it. Sun agrees, then goes directly to the park, where the woman is waiting. She gives her the money, then reveals that she knows the woman's identity: she is Jin's biological mother. The blackmailer callously shrugs this off and Sun threatens to have her father kill the woman if she reveals her existence to Jin.
Sun's pregnancy
On the island, Jack Shephard inquires about Sun's pregnancy in a manner that arouses her suspicions. Sun asks Kate Austen about Jack's loyalty. Kate suggests she talk to Juliet Burke, who reveals that pregnant women die on the island. Juliet convinces Sun to leave with her to go to. It is revealed that women who conceive on the island do not survive. Sun says Jin was infertile before coming to the island; also that she had an affair with Jae Lee before the crash. She fears revealing these facts to Jin. The tests reveal the conception took place after the crash; hence, Jin is the father. Juliet secretly leaves a message for Ben Linus on a tape recorder, explaining her findings with Sun, and promising to get a sample from Austen. She then stops the tape and whispers, "I hate you."
The parachutist
Meanwhile, Desmond Hume, Hugo "Hurley" Reyes, Jin and Charlie Pace are arguing how to care for the parachutist, Naomi Dorrit. Hurley accidentally shoots off a flare. Mikhail Bakunin, thought to have died in an earlier episode, appears shortly thereafter. He attempts to flee but Jin subdues him. The other three question him, revealing that Sayid Jarrah, Kate and John Locke told them how he'd been supposedly killed by the sonic fence. Mikhail says he was a field medic and offers to help save the parachutist's life, if they promise to let him go. The woman fades in and out of consciousness, at one point asking in Mandarin Chinese, what happened. She also tells them, in Portuguese that she is not alone. Mikhail seems to understand this but tells Desmond that she merely said "Thank you." He keeps his word and they keep theirs. Jin stops Mikhail from taking the phone. The man is allowed to leave empty-handed. The parachutist asks Hugo who he is and Hugo tells her that he was on Oceanic Flight 815. On his response she says "That's not possible" because "They found the plane. There were no survivors. They were all dead."
