Sixteen men and women attempt to persevere through weeks of challenges to become the final survivor in Thailand. In this episode: The castaways are caught off guard by a new twist.

Helen and Jan get lost while searching for a water source.

An argument raises questions about loyalty; the Red Berets show tribe members how to best use the camp's resources.

Tensions rise and accusations fly between the men and women of one tribe; the tribes compete in a reward challenge for food.

A castaway has a painful encounter with a stingray during a group swim; there's a shocking offer at the reward challenge.

The members of a secret alliance begin to suspect the others know their secret; argument over truthfulness; odd behaviour raises eyebrows.

The survivors assume the two camps will merge into one; a castaway adopts a new strategy and is accused of disloyalty; the seventh person is voted off.

One castaway gets disgusted with others' hygiene; possible alliances explored; funeral for a chicken; the eighth castaway is voted off.

News from home might impact a castaway's future; an infiltrator is recruited; the ninth castaway gets ousted.

Ted expresses his feelings about being targeted at the Tribal Council; castaways take on a four-stage obstacle course for their reward challenge.

A reward challenge takes the castaways by surprise, evoking tears of joy for the winner; the 11th person is voted out.

Rebuffed by a former ally, a castaway hatches a new strategy by enlisting support from new sources; the 12th person is voted out.

The sole survivor steps forward to claim the $1 million prize.

The 16 survivors recount what life was like on the rugged island of Koh Tarutao off the southern coast of Thailand