Stripped of everything, the 48 survivors scavenge what they can from the plane for their survival. Some panic. Some pin their hopes on rescue. A few find inner strength they never knew they had-like Kate who, with no medical training, suddenly finds herself suturing the doctor's wounds. The band of friends, family, enemies and strangers must work together against the cruel weather and harsh terrain. But the intense howls of mysterious creatures stalking the jungle fill them all with fear. Fortunately, thanks to the calm leadership of quick-thinking Jack and level-headed Kate, they have hope. But even heroes have secrets, as the survivors will come to learn.

Having escaped the "creature" and retrieved the plane transceiver, a group of the survivors travel to higher ground so they can transmit a signal. En route, they receive a mysterious transmission and encounter another of the island's inhabitants. Meanwhile, back at camp, Jack tends to a wounded man who reveals a secret about Kate.

The survivors are jolted awake in the middle of the night when wild island beasts (which are wild boars) invade the beach encampment. Kate and Michael join the mysterious Locke on a hunt for food -- and a shocking secret about Locke is revealed. On the hunt for food someone is injured. Meanwhile, some survivors are horrified by Jack's plan for the dead bodies still scattered among the wreckage -- he wants to burn them. Jack sees someone that's not there, and we find out that one of the survivors was not able to walk but now he can.

Jack, Kate and Sawyer fight over possession of a newly discovered locked metal briefcase which might contain insights into Kate's mysterious past. Meanwhile, Sayid asks a reluctant Shannon to translate notes he took from the French woman. A rising tide threatens to engulf the fuselage and the entire beach encampment, and Rose and a grieving Charlie tentatively bond over Claire's baffling kidnapping.

Hurley struggles with an assigned task inside the hatch as he flashbacks to disturbing memories in his life before the crash. Meanwhile, Sawyer, Michael and Jin learn the identities of their captors on the island. Claire uncovers a startling piece of information about the fate of the raft.

Sawyer's wound becomes life threatening as he, Michael and Jin make their way through the interior of the island with the tail section survivors.

Violence erupts when Ana Lucia and her group stumble upon Sayid and the other castaways on the island. Kate and Jack care for Sawyer when Mr. Eko brings him back to the camp himself. Flashbacks reveal Ana Lucia's troubled life.

As Kate’s backstory continues, her original crime is revealed. She thinks something is haunting her through Sawyer. Locke and Eko make an interesting discovery about the film, and Michael has a mysterious encounter with the computer.

Sun comes to a realization and 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.

Rose is surprisingly and vehemently opposed to Bernard's plan to create an S.O.S. signal; romantic sparks are rekindled between Jack and Kate when they trek into the jungle to propose a "trade" with "The Others"; and Locke begins to question his faith in the island.

While Jack devises a plan to do away with "The Others" once and for all, Sayid uncovers a flaw in "The Others'" system that could lead to everyone's rescue. But it requires Charlie to take on a dangerous task that may make Desmond's premonition come true.

The castaways are preparing for an invasion by the slightly less mysterious Others, while Charlie and Desmond find more than they were looking for in the underwater "Looking Glass Hatch".

The castaways are preparing for an invasion by the slightly less mysterious Others, while Charlie and Desmond find more than they were looking for in the underwater "Looking Glass Hatch".

The survivors feel that rescue is close at hand, but they don't know whether or not to believe Charlie's final message that the people claiming to liberate them are not who they seem to be. As unlikely alliances are formed, those they thought could be trusted may turn against them, as the enemy of their enemy becomes their friend.

Kate and Juliet must learn to work together when Jack's health is seriously compromised, and something goes wrong as Sawyer, Claire, Aaron and Miles continue their trek away from Locke's camp and back to the beach

Sayid goes back to the island to bring the rest of the people to the freighter. Ben, Locke, and Hurley go to another Dharma station in order to "move the island".

The face-off between the survivors and the freighter people continues, and the Oceanic Six find themselves closer to rescue.

The remaining island survivors start to feel the effects of the aftermath of moving the island, and Jack and Ben begin their quest to reunite the Oceanic 6 in order to return to the island with Locke's body in an attempt to save their former fellow castaways.

Hurley and Sayid are on the run from the cops after stumbling into trouble at the safehouse; the island survivors come under attack by unknown forces; and an old friend offers some shocking advice to Kate in order to ensure that "the lie" remain a secret.

Jack's decision to put a plan in action in order to set things right on the island is met with some strong resistance by those close to him, and Locke assigns Ben a difficult task.

A parallel universe, in which the crash never happened, is revealed as an aftermath of the bomb's detonation. Meanwhile, Sawyer blames Jack for the loss of Juliet and the true identity of the monster is revealed.

Locke goes in search of help to further his cause. Kate finds herself on the run, while Jack is tasked with something that could put a friend's life at risk.

Jack, the new protector of the island, meets with Locke and they go past the bamboo field with Desmond to visit the heart of the island. The Man in Black's final fate is determined, and one survivor must make the ultimate sacrifice to save the island. Meanwhile, in another life, the ones who might have been the survivors gather for a final time.

The Man in Black's final fate is determined, and one survivor must make the ultimate sacrifice to save the island. Meanwhile, in another life, the ones who might have been the survivors gather for a final time.

Rose is surprisingly and vehemently opposed to Bernard's plan to create an S.O.S. signal; romantic sparks are rekindled between Jack and Kate when they trek into the jungle to propose a "trade" with "The Others"; and Locke begins to question his faith in the island.

Hurley struggles with an assigned task inside the hatch as he flashbacks to disturbing memories in his life before the crash. Meanwhile, Sawyer, Michael and Jin learn the identities of their captors on the island. Claire uncovers a startling piece of information about the fate of the raft.

Violence erupts when Ana Lucia and her group stumble upon Sayid and the other castaways on the island. Kate and Jack care for Sawyer when Mr. Eko brings him back to the camp himself. Flashbacks reveal Ana Lucia's troubled life.

Jack, Kate and Sawyer fight over possession of a newly discovered locked metal briefcase which might contain insights into Kate's mysterious past. Meanwhile, Sayid asks a reluctant Shannon to translate notes he took from the French woman. A rising tide threatens to engulf the fuselage and the entire beach encampment, and Rose and a grieving Charlie tentatively bond over Claire's baffling kidnapping.

Jack's decision to put a plan in action in order to set things right on the island is met with some strong resistance by those close to him, and Locke assigns Ben a difficult task.

Stripped of everything, the 48 survivors scavenge what they can from the plane for their survival. Some panic. Some pin their hopes on rescue. A few find inner strength they never knew they had-like Kate who, with no medical training, suddenly finds herself suturing the doctor's wounds. The band of friends, family, enemies and strangers must work together against the cruel weather and harsh terrain. But the intense howls of mysterious creatures stalking the jungle fill them all with fear. Fortunately, thanks to the calm leadership of quick-thinking Jack and level-headed Kate, they have hope. But even heroes have secrets, as the survivors will come to learn.

Jack, the new protector of the island, meets with Locke and they go past the bamboo field with Desmond to visit the heart of the island. The Man in Black's final fate is determined, and one survivor must make the ultimate sacrifice to save the island. Meanwhile, in another life, the ones who might have been the survivors gather for a final time.

Locke goes in search of help to further his cause. Kate finds herself on the run, while Jack is tasked with something that could put a friend's life at risk.

A parallel universe, in which the crash never happened, is revealed as an aftermath of the bomb's detonation. Meanwhile, Sawyer blames Jack for the loss of Juliet and the true identity of the monster is revealed.