When Prentiss and Reid go undercover to investigate possible child abuse at an underground cult, they get trapped inside the compound when a federal raid goes bad. Luke Perry ("Beverly Hills, 90210") guest stars as cult leader Benjamin Cyrus.
Desmond experiences unexpected side effects when he and Sayid hit turbulence on the way to the freighter.
The members of Oceanic 6 discover how to get back to the island, but not all of them want to return.
Sayid confronts Ben's spy aboard the freighter; Ben urges Alex to leave Locke's camp.
Juliet must reveal some surprising news to Jin when Sun threatens to move to Locke's camp; Desmond and Sayid meet the ship's captain and begin to get an idea of the freighter crew's mission.