Survivor: Cook Islands is the thirteenth season of the American CBS competitive reality television series Survivor . During this season of Survivor , the 20 contestants were divided into four tribes by ethnicity (African American, Asian American, Hispanic American, and European American). These four tribes were named some of the islands located in the Cook Islands: Manihiki, Puka Puka, Aitutaki, and Rarotonga. The four tribes evenly divided into two new mixed tribes after the second tribal council, taking the Aitutaki and Rarotonga names. A mutiny offer was made to all remaining players during before the merge; two of the players on the same tribe accepted. After the nine remaining contestants merged, they decided to name themselves Aitutonga. This season also featured the first time a tribe has voted off two members during a single tribal council. The concept of Exile Island returned, with a hidden immunity idol located somewhere on the island. Instead of the usual final two players facing a jury of seven, there was a final three facing a jury of nine, which included players who had been voted out before the merge.

The 13th edition of the reality series strands 20 people on the Cook Islands in the Pacific to vie for the $1 million grand prize. Initially, the castaways are divided into four ethnically diverse groups (African-American, Asian-American, Hispanic and white).

One tribe member becomes dehydrated due to a lack of fire to purify drinking water. In the Aitutaki camp, the members consider throwing the immunity challenge so they can vote Billy out. Castaways from the Puka Puka tribe become increasingly annoyed with Cao Boi's controversial comments. At tribal council, the second person is voted off of the islands.

An unexpected twist sends the castaways scrambling for new alliances.

One tribe finds itself divided by gender.

One tribe finds its way to the other tribe's island.

Win or lose, both tribes must vote one of their own off the island.

A recap of the first half of the season includes previously unseen footage of Candice and Adam getting stranded on a sandbar in a boat due to a storm. Also: Stephannie gets drunk following a reward challenge; Jonathan, Adam and Candice search in vain for the immunity idol.

One castaway collapses at the Reward Challenge.

At the Reward Challenge, the remaining castaways are given the opportunity to leave their current tribe and join the opposing tribe.

A sealed message in a bottle leads one tribe to an unexpected twist.

The tribes merge and Yul attempts to change the course of the game.

With only eight castaways left, Jonathan is in the hot seat with certain tribe members after turning on his former alliance.

With only seven castaways left, the Loved Ones arrive in hopes of winning the reward.

With only six castaways left, outsiders Parvati and Adam fight to stay in the game.

The SURVIVOR: COOK ISLAND's finale will begin with five castaways and the winner determined among the final three when the series finale is broadcast on a special night.

The winner is revealed as the 20 castaways reunite and are questioned by host Jeff Probst.