Lost

The survivors begin to learn the island's secrets. Jack, Charlie and Kate venture into the dark heart of the jungle to try and recover the airplane transceiver. But even heroes have secrets, as the survivors will soon learn.

Having escaped the creature and retrieved the transceiver, the survivors travel to higher ground so they can transmit a signal. Soon they receive a mysterious transmission and encounter one of the island's inhabitants.

Jack and Hurley discover a secret about Kate; the marshal's life hangs in the balance; some of the survivors ponder the mysteries they have uncovered; Locke' befriending of Walt disturbs Michael.

Locke hunts for food and someone on the hunt is injured; a secret about Locke is revealed; some survivors are horrified by Jack's plan for the dead bodies still scattered among the wreckage.

Jack struggles to overcome the events that brought him to Australia; Boone gets caught in a riptide trying to save a woman who went swimming. Claire is very dehydrated and a thief may have stolen the last of the water.

There's shock when Michael's beaten, but only non-English-speakers Jin and Sun know the truth about the attack. Kate, Jack, Sawyer and Sayid argue about where the survivors should camp. Locke discovers Charlie's secret.

Aided by Locke, Charlie begins withdrawing from drugs; there's a struggle to find and free Jack when he's buried alive in a cave collapse; someone might be sabotaging the plan to find the source of the French transmission.

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 him.

Sayid's life is placed in grave danger after he stumbles upon the source of the mysterious French transmission, the woman Danielle Rousseau.

Claire has a horribly realistic nightmare about her new baby being harmed or kidnapped. Flashbacks reveal Claire's backstory.

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

Jack, Kate and Sawyer fight over possession of a newly discovered locked metal briefcase which might contain insights into Kate's mysterious past.

Locke learns Boone wants to share their secret with Shannon and decides to teach him a lesson. Boone and Shannon's dark past is revealed. Kate is puzzled by Sun's behaviour and the revelation that she can speak English.

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

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

Kate and Sawyer divulge dark secrets to each other while tracking a renegade boar that Sawyer swears is purposely harassing him.

The raft the survivors have been building burns and Michael is convinced that Jin is responsible; Sun makes a revelation; Boone warns Sayid about Shannon. Details of Jin and Sun's troubled marriage are revealed.

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.

Locke thinks he's being sent a sign on how to get the hatch open, and he and Boone venture inland.

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.

After another funeral, tempers rise as the survivors' suspicions of each other grow, and an unlikely survivor vows revenge.

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.

The French woman stuns the survivors when she shows up with a dire warning about "The Others'', while Michael and Jin ready the raft for sailing.

Something unexpected at sea surprises those on the raft; the remaining islanders try to blow open the hatch.

In the finale to the first season, a visitor to the encampment could be a threat to Claire's infant son.