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 K…

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 …

Jack and Hurley discover an alarming secret about Kate, as the marshal's life hangs in the balance and he suffers a lot of pain. Meanwhile Kate, Charlie, Sawyer, Sayid, Boone and Shannon ponder the my…

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 -- a…

Jack is nearly delirious from lack of sleep and struggles to overcome the haunting events that brought him to Australia and, subsequently, to the island. Meanwhile, Boone gets caught in a treacherous …

Walt and the others are shocked when Michael is brutally beaten, but only the non-English-speaking Jin and Sun know the truth behind the attack. Meanwhile Kate, Jack, Sawyer and Sayid argue about wher…

Charlie begins a painful journey of withdrawal from drugs, surprisingly aided by Locke, whose true motive for helping Charlie is a mystery. Meanwhile, survivors struggle to find and free Jack when he'…

Shannon's inhaler runs out and Boone believes Sawyer has the remaining three in his stash. When Sawyer refuses to give them up, Jack and Sayid resort to torturing Sawyer until he agrees to reveal the …

Sayid's life is placed in grave danger after he stumbles upon the source of the mysterious French transmission, the woman Danielle Rousseau (guest-star Mira Furlan). She was on the distress call and i…

Claire has a horribly realistic nightmare about her new baby being harmed or kidnapped. Flashbacks reveal Claire's backstory: the former boyfriend who got her pregnant, then abandoned her, and the psy…

Survivors wonder why Charlie and Claire have been abducted - and by whom - and a search party ventures into the treacherous jungle to look for the pair. Suspicions focus on Ethan Rom (guest-star Willi…

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 translat…

When Locke learns that Boone wants to share their "secret" with Shannon, Locke decides to teach him a lesson. This leads to Shannon's life being placed in what seems like peril. Boone and Shannon's …

Violence ensues and a mysterious island beast makes a re-appearance when Michael and Locke clash over Walt's upbringing. Meanwhile, Charlie is tempted to read the missing Claire's diary, and Sayid enl…

After the missing Claire returns with no recollection of what has happened since before she boarded the doomed Oceanic flight 815, Jack and Locke formulate a plan of defense against her kidnapper, the…

Kate and Sawyer divulge dark secrets to each other while tracking a renegade boar that Sawyer swears is purposely harassing him. Hurley and Sayid worry that Charlie is losing it after facing a brush …

When the raft the survivors have been building mysteriously burns down, Michael is convinced that Jin is responsible for the sabotage, which only serves to escalate their rivalry. Meanwhile, Sun stuns…

When Hurley becomes obsessed with the French woman and heads into the jungle to find her, Jack, Sayid and Charlie have no choice but to follow. Hurley flashes back to the hugely life-altering experien…

Locke thinks he's being sent a sign on how to get the hatch open, and he and Boone venture inland. Jack is reluctant to offer assistance when Sawyer begins to experience excruciating headaches and nee…

Jack tends to a severely wounded Boone after Locke returns him to the caves. In the confusion, Locke slips away to deal with his guilt over the crisis. Meanwhile, Claire unexpectedly goes into labor …

After another funeral, tempers rise as the survivors' suspicions of each other grow, and an unlikely survivor vows revenge. The events that landed Sayid on Flight 815 play out as he engages Locke in a…

Jack suspects foul play when Michael becomes violently ill while building the raft. The suspects include Sawyer and Kate, who compete for the last seat on the raft and do anything possible to prevent …

The French woman-Danielle Rousseau-shocks the survivors by showing up to the camp with a dire warning about "the Others" who are on the island, and the black smoke that precedes them. Meanwhile, Micha…

The castaways on the raft are surprised at sea by something unexpected. Meanwhile, remaining islanders attempt to blow open the hatch, and a visitor to the encampment might be a threat to Claire's inf…

Jack, Locke and Kate explore the mysterious hatch but Jack decides to wait before going down into the hatch. Kate and Locke aren't so patient. When Shannon chases after Vincent the dog, she encounters…

With the abduction of Walt fresh on their minds, their raft destroyed, and Jin missing, Michael and Sawyer fight for their lives in the middle of nowhere in the ocean and discover a new predator in th…

Michael, Sawyer, and Jin find themselves prisoners after they encounter what they believe to be a group of Others. At the Hatch, the group learns more about their new surroundings but are confused at …

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 o…

The tail-section survivors trek back to the southern beaches of the Island, but encounter trouble as Michael sets off by himself to find Walt. Meanwhile, at the main camp, Sun is heartbroken as she re…

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. Meanwhile, Shannon is once again haunted by visions of…

The harrowing first 48 days in the lives of the tail section survivors are revealed. Flashbacks reveal the point of view of Ana-Lucia, Mr. Eko, Bernard and Libby and other survivors as they landed on …

Violence erupts when Ana Lucia and her group stumble upon Sayid and the other castaways on the island. Ana Lucia holds Sayid captive. Kate and Jack care for Sawyer when Mr. Eko brings him back to the …

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 myste…

When Eko finds Charlie's Virgin Mary statue, he demands that he take him to where he found it at once. Michael continues to communicate on the Swan computer without the other survivors knowing.

Jack, Locke and Sawyer follow after a determined Michael after he heads into the jungle toward the dreaded "Others" in search of Walt. Meanwhile, Sun has a surprising reaction to Jin's desire to join …

When Charlie's vividly surreal dreams lead him to believe Claire's baby, Aaron, is in danger, Locke suspects Charlie may be using again. Meanwhile, Sawyer encourages Hurley to act on his attraction to…

Some of the island survivors fear that "The Others" may have returned when Sun is greatly injured during a failed kidnapping attempt at her plant garden. Also, the trust barrier becomes very thin betw…

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 t…

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 …

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 int…

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…

Libby lends a helping hand to Hurley to support him when he begins to think the island is having a strange effect on him. Hurley begins to see Dave (guest-star Evan Handler, Sex and the City) on the i…

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 "…

After finding an exhausted Michael in the forest, Jack and Kate bring him back to the main camp. When he finally wakes up, Michael has some new details about "The Others." Also, a lovestruck Hurley pl…

Mr. Eko has dreams about his brother leading him somewhere. He seeks Locke's help in finding a secret location, the "question mark." Meanwhile, Jack and the other survivors grapple with the horrific s…

A determined Michael convinces Jack and several castaways to help him rescue Walt from "The Others." With Jack away, Locke is left in charge of the hatch and must decide if he should believe Henry and…

After discovering something odd just offshore, Jack and Sayid come up with a plan to confront "The Others" and hopefully get Walt back. At the same time there will be an answer to the question of wher…

After discovering something odd just offshore, Jack and Sayid come up with a plan to confront "The Others" and hopefully get Walt back. Meanwhile, Eko and Locke come to blows as Locke makes a potentia…

Jack, Kate, and Sawyer are prisoners of the mysterious "Others." After their captors drug them and take blood samples, they are held in separate areas. The camp leaders--Ben (Henry Gale), Mr. Friendly…

Sun and Jin's lives are put in danger when Sayid tries to locate Jack and the other missing castaways. Sayid also creates a plan in order to get the attention of the "Others" on the beach. Meanwhile, …

Locke, Eko and Desmond are found scattered about the island after the implosion of the hatch. Locke receives a message from the Island asking him to fix the situation he caused. Hurley returns to the…

The Others prevent Sawyer and Kate from escaping, leaving Sawyer perplexed by the extent of the measures taken to keep them imprisoned. Jack is asked to use his medical training to save the life of on…

A delirious Eko wrestles with past demons; some of the castaways go to the Pearl station to find a computer they can use to locate Jack, Kate and Sawyer; Jack does not know who to trust when two of th…

Jack makes a decision regarding Ben's offer. Sawyer's life is placed in danger when Pickett decides to make good on his threat. Locke discovers a hidden message that may help unlock the island's secre…

Jack has the Others in a desperate situation as he holds Ben's life in his hands. Meanwhile, Kate and Sawyer try to escape from their captors. Flashbacks reveal Juliet's past as a medical researcher …

After Desmond rescues Claire from drowning, Charlie gets Hurley to help him find out why Desmond has seemed able to predict the future. Desmond recalls exactly what took place in the moments after he …

As Kate and Sawyer journey back to the main island with Karl, who is exhibiting effects of the brainwashing video, they argue over whether to go back and save Jack. On Hydra island, as Juliet's fate r…

Kate is still struggling over their decision to leave Jack in the hands of the Others as she and Sawyer return to their camp. Meanwhile, Hurley finds an old van in the jungle and attempts to use it t…

On their mission to rescue Jack, Kate, Sayid, and Locke stumble upon a mysterious structure surrounded by farm animals and meet its strange inhabitant. Back at the camp, in order to reclaim his belong…

Claire has an idea to send a message to the outside world. Charlie, however, is resistant to the idea, and Desmond tries to sabotage the plan. As Claire tries to get the truth behind their actions out…

When Kate and Locke arrive at the Others' camp, Ben promises to tell Locke the island's secrets as long as he stops his destructive plan, and Kate's reunion with Jack doesn't go very well when she lea…

As the truth about Sun's kidnapping by "the Others" comes to her attention, Hurley becomes suspicious of Sawyer's attempt to reveal the mystery behind two fellow survivors, Nikki and Paulo. Through se…

Kate and Juliet are stranded in the jungle after Kate learns that there is a traitor in the survivor's midst. Meanwhile, Sawyer's poor attitude and selfish ways towards the beach community may earn hi…

The celebration of Jack's return is cut short when he arrives at the beach with an Other, Juliet, whose flashbacks pick up from where they left off, showing us how she got onto the island and became a…

Desmond convinces Hurley, Jin, and Charlie to follow him on a trek through the jungle after he receives a series of visions. Flashbacks reveal the time that Desmond spent with a cloister of monks. Mea…

Sun allows Juliet to examine her when she learns that all of "The Others" pregnant woman died before they gave birth on the island. Meanwhile, Desmond and an unlikely nemesis collaborate to save a new…

After abandoning the Others, Locke takes Sawyer on a trek through the jungle to help him eliminate a common enemy. Meanwhile, back at the beach, the parachutist Naomi has crucial information about fli…

Ben unwillingly divulges information to Locke about the island, taking him on a journey to various locations including strange monuments and the mysterious Jacob. Back at the beach, Juliet's secret is…

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 danger…

The season 3 finale finds the castaways 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 Glas…

The season 3 finale finds the castaways 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 Glas…

They thought they had met the enemy. They thought they had seen evil. They thought wrong. As the new season begins, the survivors feel that rescue is close at hand, but they don't know whether or not …

The survivors begin to question the intentions of their supposed rescuers when four strangers arrive on the island.

Locke's hostage may be the key to getting off the island, so Sayid and Kate go in search of their fellow castaway in an attempt to negotiate a peaceful deal.

Kate needs to get information out of the hostages, but it may jeopardize her standing with Locke -- as well as with Sawyer. Meanwhile in the future Kate's Court hearings take place.

Sayid and Desmond hit a bit of turbulence on the way to the freighter, which causes Desmond to experience some unexpected side effects.

Juliet receives an unwelcome visit from someone from her past and is given orders to track down Charlotte and Faraday in order to stop them from completing their mission -- by any means necessary. Mea…

Juliet is forced to reveal some startling news to Jin when Sun threatens to move to Locke's camp. Meanwhile, Sayid and Desmond begin to get an idea of the freighter's crew when they meet the ship's ca…

Sayid confronts Ben's spy on the freighter, and Ben urges daughter Alex to flee Locke's camp in order to survive an impending attack.

Jack tries to discover the identity of a body that has washed ashore. Meanwhile, Locke's camp is attacked by Ben's adversaries.

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…

Locke finds out where Jacob's cabin is. Life on the freighter becomes dangerous.

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'…

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 …

Desmond looks for a woman who might be the key to helping Faraday stop the island's unpredictable movements through time; Locke finds out who has been attacking the survivors.

Kate discovers that someone knows the secret of Aaron's true parental lineage. Meanwhile, the dramatic shifts through time are placing the lives of the remaining island survivors in extreme peril.

Locke shoulders the burden of ending the island's increasingly violent movements through time; Ben is stymied in his efforts to reunite the Oceanic 6 and bring them back to the island.

The members of Oceanic 6 discover how to get back to the island, but not all of them want to return.

Locke's mission off the island as Jeremy is revealed.

Sawyer perpetuates a lie with some of the other island survivors in order to protect themselves from mistakes of the past.

After meeting old acquaintances Sawyer is forced to continue lying to protect them.

Everyone on the island is at risk when one of the survivors decides to go against them and taking matters into their own hands.

Kate goes to extreme measures to save Ben's life when Jack refuses to help. Meanwhile, Kate begins to tell the truth about the lie in order to protect Aaron.

To atone for sins of the past, Ben must attempt to summon the smoke monster in order to be judged.

Suspicions about a possible breach intensify after Ben is taken from the infirmary, and a reluctant Miles is forced to work with Hurley when he's asked to deliver an important package to a top Dharma …

On the 100th episode milestone for the series, the time of reckoning has begun when Daniel Faraday comes clean regarding what he knows about the island.

Jack and Kate find themselves at odds over the direction to take to save their fellow island survivors, Locke further solidifies his stance as leader of "The Others," and Sawyer and Juliet come under …

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.

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.

Two outcomes of the detonation of the hydrogen bomb are presented. Flight 815 lands safely at LAX, where Kate escapes from the marshal and Jack learns that his father's body was lost in transit.

Jack, Sawyer, Kate, Miles and Hurley, struggling to save Sayid, face an ancient secret. Meanwhile, a fake Locke exits the chamber to everyone's awe.

When Sawyer escapes from the temple, Kate and Jin are sent to bring him back. Meanwhile, the Others determine Sayid is infected and attempt to poison him. In the flash sideways, Kate, still on the run…

On the island, the Man in Black attempts to recruit Sawyer in his attempt to leave the island, while an impromptu funeral is held for the real Locke. In the flash sideways, Locke is fired from his job…

On Jacob's orders, Hurley leads Jack to a lighthouse. Meanwhile, Claire questions an Other she has captured while tending to an injured Jin. In the flash sideways, Jack is a single father trying to bo…

After recruiting Sayid to his cause, the Man in Black issues an ultimatum to the Others: either join him or die. Meanwhile, Kate is reunited with Claire. In the flash sideways, Sayid helps his brother…

Ilana discovers Ben killed Jacob, so she plans to kill him. Meanwhile, Jack, Hurley and a suicidal Richard visit the Black Rock. In the flash sideways, Ben, a high school teacher, tries to blackmail t…

The Man in Black sends Sawyer on a reconnaissance mission to Hydra Island, where he discovers that Charles Widmore has returned to the island with a team of scientists. In the flash sideways, Sawyer i…

Richard Alpert's back story is shown: In 1867, he is brought to the island on the Black Rock as a slave. He makes a deal with Jacob to be his representative in exchange for immortality. In the present…

After Jin is kidnapped and taken to Hydra Island by Widmore's team, the Man in Black confronts Widmore. On the main island, Sun loses her ability to speak English. In the flash sideways, Sun and Jin a…

On the island, Widmore subjects Desmond to a large amount of electromagnetic energy as an experiment. In the flash sideways, Desmond, with the aid of Charlie, starts to have visions of his life in the…

In order to prevent more loss of life, Hurley leads the other survivors to speak with the Man in Black. In the flash sideways, Hurley meets Libby, while Desmond continues his mission to let the Oceani…

The survivors split into two groups; one led by Sawyer, the other by the Man in Black. Sawyer's group travels to Hydra Island, where they are captured by Widmore's crew after Sun and Jin are reunited.…

After the remaining survivors are reunited, Sawyer and Jack hatch a plan to divert the Man in Black's attention and leave the island without him on Widmore's submarine, but disastrous consequences awa…

Jacob and the Man in Black are revealed to be twin brothers. They are raised by a mysterious woman who is charged with protecting the island. As revenge for the murder of their adoptive mother (who ki…

Ben finally takes his revenge on Widmore after accepting the Man in Black's request for assistance. Jacob explains the purpose of the candidates, and Jack volunteers to take his place. The search for …

For different reasons, Jack and the Man in Black both use Desmond to extinguish the light at the heart of the island. The island starts disintegrating, but The Man in Black is also made mortal. Still …