Locke puts his plan into action, which could liberate him from the island.

Jack's decision to set things right on the island is met with strong resistance.

Jack and Kate are at odds over the direction to take to save their fellow island survivors, and Locke further...

The time of reckoning has begun when Daniel Faraday comes clean regarding what he knows about the island.

Suspicions about a possible breach intensify after Ben is taken from the infirmary, and a reluctant Miles is...

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

Kate goes to extreme measures to save Ben's life when Jack refuses to help.

A survivor goes rogue, endangering the lives of everyone on the island.

Sawyer further perpetuates his lie in order to protect the Oceanic 6.

Sawyer perpetuates a lie with some of the other island survivors.

Sawyer perpetuates a lie with some of the other island survivors.

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

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

The way back to the island is revealed to members of the Oceanic 6.

The way back to the island is revealed to members of the Oceanic 6.

Ben hits a roadblock in his attempt to reunite the Oceanic 6.

Ben hits a roadblock in his attempt to reunite the Oceanic 6.

Kate learns that someone knows the secret of Aaron's parentage.

Kate learns that someone knows the secret of Aaron's parentage.

A woman may be the key to Faraday stopping the island's erratic movements.

A woman may be the key to Faraday stopping the island's erratic movements.

Jack and Ben begin their quest to reuinite the Oceanic 6.

Ben, Locke, and Hurley go to The Orchid and are met by Keamy and his men.

Locke, Ben, and Hurley continue their search for the cabin.

Juliet is forced to perform an emergency appendectomy on Jack.

The team from the ship attacks Locke's camp looking for Ben.

Ben tells Danielle and Alex to leave camp and go to the island temple.

Juliet exposes Sun's pre-island affair to Jin.

Daniel and Charlotte leave Jack's camp to fulfill their objective.

Desmond's consciousness begins jumping back and forth.

Kate goes behind Locke's back to arrange a meeting between Miles and Ben.

Sayid negotiates a deal with Locke so that he can reach the ship.

The surviving members of the "rescue team" are scattered around the island.

The survivors wait for Charlie to turn off the signal-jamming device.

The survivors discover that an attack is more imminent than expected.

Ben takes Locke to see Jacob and reveal the island's secrets.

Locke tells Sawyer that he needs to come with him to kill Ben.

An unlikely person helps Desmond save the life of a woman.

Desmond's latest vision suggests that Penny will land on the island.

Jack takes Juliet back to their camp.

"The Others" leave Juliet behind, handcuffed to Kate in the jungle.

Nikki and Paulo have their backstory revealed.

Jack tells Kate that he has made a deal with "The Others."

Sayid, Locke and Kate scale "The Others'" protective perimeter.

Sayid, Locke and Kate find another Dharma station.

Hugo enlists Sawyer's help with an old VW van found on the island.

Ben has an infection, and Jack negotiates the freedom of Juliet.

Charlie and Hurley suspect that Desmond can see the future.

Jack sabotages Ben's surgery.

Kate desperately tries to protect Sawyer from being killed by "The Others."

Mr. Eko returns to the site of his brother's plane crash.

"The Others" perform a medical procedure on Sawyer.

Locke experiences visions of Boone.

Sayid attempts to rescue Jack, Kate and Sawyer from "The Others."

Jack and Sayid come up with a plan to confront "The Others."

Locke struggles with a choice whether or not to abandon the hatch.

Mr. Eko enlists Locke to find a secret location he believes houses answers.

Ana Lucia attempts to get Henry Gale to confess to being a spy.

Jack proposes to "The Others" a trade of Henry for Walt.

Hurley begins to think the island is affecting him.

Locke is trapped and forced to enlist the help of an unlikely ally.

Sun comes to the realization that she might be pregnant.

Claire becomes determined to find out what happened to her.

Danielle Rousseau returns to lead Sayid to a mysterious captive.

Survivors fear that "The Others" may have returned when Sun is injured.

Locke suspects Charlie may be using drugs again.

Jack, Locke and Sawyer track Michael while he looks for his son.

Mr. Eko exposes Charlie's secret to Claire.

Kate's original crime that started her life on the run is revealed.

Ana Lucia and her group stumble upon Sayid and the other castaways.

The first 48 days in the lives of the tail section survivors are revealed.

Sawyer's wound becomes life-threatening as they travel through the island.

A desperate Michael sets off into the jungle to find Walt.

Sawyer, Michael and Jin discover the identities of their captors.

Sawyer, Michael and Jin wonder if their captors are the "Others."

Michael blames Sawyer for the abduction of Walt.

We flashback to the survivors final moments before they boarded the plane.

A secret from Kate's past is revealed to the other survivors on the island.

Sayid engages Locke to uncover the truth about Boone's death.

Claire unexpectedly goes into labor while deep in the forest.

Locke thinks he's being sent a sign on how to get the hatch open.

Sun stuns her fellow survivors with a surprising revelation.

A shocking connection between Sawyer and Jack is revealed in a flashback.

Ethan threatens to kill other survivors unless Claire is returned to him.

Sayid enlists Shannon to help decipher the French woman's map.

Kate is puzzled by the revelation that Sun can speak English.

A rising tide threatens to engulf the entire beach encampment.

Boone and Locke discover another island mystery.

Flashbacks reveal Claire's backstory.

Hurley flashes back to the experience he had before boarding the plane.

We flash back to Sayid's childhood friend Nadia.

In flashback we hear Sawyer's story and find he is not who he says he is.

Survivors struggle to free Jack when he's buried alive in a cave collapse.

Locke discovers Charlie's secret.

A pregnant Claire's health takes a bad turn from lack of fluids.

A shocking secret about Locke is revealed.

Kate flashes back to when she was arrested by the marshal in Australia.

Jack tends to a wounded man who reveals a secret about Kate.

The 48 survivors scavenge what they can from the wreckage of their plane.

Jack's decision to set things right on the island is met with some strong resistance by those close to him,...