The castaways who make it onto the raft are surprised at sea by something that unexpectedly happens -- they make their first contact with "others" out at sea, but meet disastrous results. Meanwhile, remaining islanders attempt to blow open the hatch that's in the forest, but this proves to be more difficult than expected. Another survivor on the island dies. Visiting French woman Danielle Rousseau becomes a threat to Claire's infant son as she decides to kidnap him and bring him into the woods for "the others" to have in order to save the rest. Lastly, flashbacks show us all the survivors in the moments before the doomed flight took off.

Source: ABC