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 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. But who can be trusted? Is rescue really as close as it seems?

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.

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. Meanwhile, Ben offers Locke an enticing deal.

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 captain.

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 to the beach

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.