Ben confronts Jack, claiming that Naomi is not who she seems. Meanwhile, Sawyer and Juliet try to come up with a plan to rescue the hostages at the beach. Inside the Looking Glass, Charlie and Desmond struggle to finish the mission at the underwater station.

Jack and the castaways begin their efforts to make contact with Naomi's rescue ship.

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.

Ben begrudgingly begins to introduce Locke to the secrets of the island, beginning with the mysterious Jacob. Meanwhile, Juliet's secret goes public.

A newly focused Locke breaks away from "The Others" in an attempt to persuade Sawyer to help rid them of a great nemesis that has caused nothing but pain in both of their lives. Meanwhile, a new island inhabitant discloses some shocking information about Oceanic Flight 815.

After discovering that all of "The Others'" pregnant women died before giving birth on the island, an extremely reticent Sun allows Juliet to examine her -- and uncovers the identity of the unborn child's father. Meanwhile, Desmond allows an unlikely nemesis to help save the life of a new, mysterious island inhabitant.

Desmond coaxes Charlie, Hurley and Jin on a trek across the jungle after experiencing one of his future-prophesizing "flashes" -- but is he purposely placing Charlie's life in harm's way? Meanwhile, Kate turns to an unwitting Sawyer after seeing Jack alone with Juliet.

Jack's joyous reunion with his fellow survivors is cut short when they realize that accompanying him is one of 'The Others,' and Claire is stricken by a mysterious, life-threatening illness.

After discovering that one of her own has betrayed her to 'The Others,' Kate is left to fend for herself in the jungle with Juliet. Meanwhile, Hurley warns Sawyer to change his selfish ways and make amends with his fellow survivors or he may face a vote of banishment.

Hurley begins to suspect that Sawyer may be involved in an island mystery surrounding two fellow survivors, and Sun learns the truth about her past kidnapping attempt by -The Others-.

Ben tries to persuade a determined Locke to call off his destructive plan by offering him some of the secrets of the island, and Kate�s reunion with Jack does not go off as planned when she discovers that he has made a deal with -The Others-.

Claire becomes suspicious of Charlie when he exhibits peculiar behavior after she comes up with an idea that could get everybody rescued. Meanwhile, tensions mount between Sayid and Locke as they continue their trek to rescue Jack.

Locke, Sayid and Kate investigate a strange structure and its mysterious inhabitant. Meanwhile, Sawyer competes in a ping-pong competition to get back his belongings.

Hurley's discovery of an old, wrecked car on the island leads him on a mission of hope not only for himself, but for a fellow survivor in need of some faith. Meanwhile, Kate and Sawyer reunite with their fellow castaways, but Kate is still torn about leaving Jack behind with "The Others."

A power play ensues between Jack and 'The Others' as Juliet's future hangs in the balance. Meanwhile, Kate, Sawyer and Karl continue on their journey away from 'Alcatraz.'

A suspicious and determined Hurley enlists Charlie to help him wrangle the truth out of Desmond, who has been acting strangely ever since the implosion of the hatch.

While Jack is in command as the fate of Ben's life rests in his hands, Kate and Sawyer help Alex in return for a boat, and Juliet makes a shocking decision that could endanger her standing with her people.

As Jack considers whether or not to treat Ben, he is motivated by Kate's claims that if he does not comply, Pickett will kill Sawyer

A delirious Eko wrestles with demons from his past, while Locke and some of the other castaways head back to The Pearl -- one of the Dharma Initiative's island stations -- hoping to find a computer that they can use to locate Jack, Kate and Sawyer. Meanwhile, Jack doesn't know whom to trust when two of 'The Others' seem at odds with one another.

Sawyer's rebellious attitude causes Ben and the Others to conjure a plan to keep him in check. At the beach, Desmond starts to mysteriously seek certain items for some kind of construction

The fates of Locke, Eko and Desmond are revealed after the implosion of the hatch, while Hurley returns to the beach camp to tell the tale of what happened when he, Jack, Kate and Sawyer encountered "The Others".

Jin, Sun and Sayid worry when Jack, Kate and Sawyer make no contact with them after they have lit the signal fire. Meanwhile, the Others realize that the survivors have acquired a sailboat.

In the season premiere episode, "A Tale of Two Cities", Jack, Kate and Sawyer begin to discover what they are up against as prisoners of "The Others".