Event Year: 2004

When the hatch suddenly takes on a life of its own, Locke is forced to enlist the help of an unlikely ally to control the matter. Meanwhile, Ana Lucia, Sayid and Charlie go off into the jungle to find out the truth about Henry Gale and see if there really is balloon craft out there in the jungle that carried him and his wife to the island.

Sun comes to the realization that she might be pregnant. She struggles on whether to tell Jin about the situation. Meanwhile, with no success from Jack or Sayid, Ana-Lucia is called in by Locke to interrogate the new prisoner Henry Gale to get more information out of him about the balloon that he and his wife supposedly landed on the island with.

A mysterious illness that baby Aaron suddenly contracts sends a desperate Claire, Kate and French woman Danielle to return to the same area where Claire was initially kidnapped. It is there where she believes she can find a cure for Aaron's illness. In the meantime, Jack and Locke are doing their best to keep their prisoner a secret from the rest of the survivors on the island.

After Sun is attacked, some of the survivors begin to think that one of the "other survivors" might be one of "The Others." When French woman Danielle Rousseau leads Sayid to a mysterious captive in the jungle, he becomes determined to find out if he is one of "The Others". Meanwhile, Sawyer discovers Hurley’s potentially devastating breach of the survivors’ trust and blackmails him into helping track an elusive island creature that won’t leave Sawyer alone.