Survivor: Blood vs. Water is the twenty-seventh season of the American CBS competitive reality television series Survivor, which premiered on Wednesday, September 18, 2013. The season features returning castaways and their family members competing against each other. It is the third consecutive season, and the ninth season overall, to feature returning contestants. As with the previous two seasons, the season was filmed in the Philippines, but this time at Palaui Island, Cagayan. The tribe names are Galang and Tadhana, which mean respect and destiny in Tagalog, respectively.

A modified version of Redemption Island, a twist formerly seen in Survivor: Redemption Island and Survivor: South Pacific, was utilized after a three-season hiatus. In this season, remaining contestants may choose to switch places with their partner if their partner is on Redemption Island. The game began with a twist called Day Zero, in which each of the ten pairs was marooned in a separate location, spending the night together before congregating as a full cast the following morning and dividing into two tribes. Due to this twist, this season is one of two to last longer than 39 days, after Survivor: The Australian Outback which lasted 42.

Episode 1: "Blood Is Thicker Than Anything"
Immunity Challenge: Six castaways from each tribe would race out into the ocean and over a set of three obstacles to a boat. They would then dive down to untie knots to free the boat. The castaways would paddle the boat back to shore and deliver a chest with three bags of puzzle pieces. The other three members of the tribe would then assemble the puzzle pieces into a ship's wheel which would be used to raise a flag. The first tribe to raise their flag would win.

The ten pairs of returning players and their loved ones were dropped off in ten separate locations as part of the Day Zero twist to spend the night together without a tribe. The next morning, Jeff welcomed the twenty castaways to the game and announced that they would not be playing the game with their loved ones, but against each other. The castaways split into their tribes and Jeff sprung a second twist on them that they would immediately vote out a member of their tribe. Tadhana voted out Laura B. while Galang voted out Candice. Jeff then announced that Redemption Island was back in play, but with a twist that the loved one of the castaway could switch places with them. Rupert immediately stepped forward to take his wife's place and she joined Galang. After discussing it between themselves, John did not switch with Candice. At their new campsite, Brad arranged an all-boy's alliance at Tadhana. At the Immunity Challenge, Gervase struggled with the swimming part of the challenge, giving Tadhana a huge lead at the end of the boat stage of the challenge. The lead was squandered during the puzzle stage as Laura M., Monica, and Tina worked efficiently to solve the puzzle to give Galang the win. Gervase's excessive celebration at the win did not go over well with Tadhana and that put a target on Marissa, despite her comments against her uncle's actions. The boy's alliance knew from day one that they wanted to vote out one of the women and was trying to decide between Katie, who was seen as ineffective at the puzzle stage of the challenge, and Marissa, who was guilty by association for Gervase's excessive celebration. In the end, the boy's alliance went with Marissa and she was blindsided by a vote of 8–1. She headed off to Redemption Island to face Candice and Rupert.