Netflix's The Survivors twisty ending explained

The show begins with Kieran and his partner Mia returning to their hometown to introduce his parents, Verity and Brian, to their new baby daughter, Audrey. It is difficult for Kieran to return to his hometown, as 15 years earlier his older brother, Finn, and his friend, Toby, attempted to save him from drowning at high tide at the local caves. While Kieran survived, Toby and Finn both died in their attempt and are known among the community as heroes.

Meanwhile, on the same day Mia's best friend, Gabby, also went missing with police deciding that she was swept into the ocean and drowned after her backpack was discovered washed up on the shore.

Upon his return home, Kieran meets a newcomer on the island, Bronte, who is staying with Gabby's mother Trish and sister Liv, and has been looking into the murders. The following day she is discovered dead on the beach, sparking a murder investigation.

The series throws out several red herrings about the culprit behind Bronte's death, including a Brazilian backpacker she was romantically involved with, and a disgraced novelist who has recently moved to the island and is working on a book about Gabby's disappearance.

Kieran's father Brian is also a suspect. With advancing dementia, he was on the beach on the night of Bronte's death, and his DNA is found on her mouth and chest, leading to his arrest. Their beach hut was also defaced and broken into, and Bronte's camera was found there, further implicating Brian in her murder. 

It is also revealed that the sergeant originally looking into Gabby's death lied to her mother about where she was on the day of the death, as he discovered her backpack in Toby and Finn's boat's locker. Realising the implications that Gabby, who was underage at the time, drowned with them on the boat, he threw her backpack into the ocean and claimed that it was washed up to shore.

It was also confirmed that while Toby and Finn did try to save Kieran, it wasn't Kieran who called them, but Liv, who had been in the caves with him when the tide came in. Kieran and Liv had never told anyone that she was there, and she avoided being blamed for any culpability in their deaths.

It is ultimately revealed that while Brian was on the beach on the night of Bronte's death, he tried to save Bronte's life after discovering her in the ocean. As a former PE teacher and lifeguard, his instinct kicked in to perform CPR, despite his dementia, which is why his DNA was on her body. The bright light he saw was from a torch being used by the real culprit.

It is ultimately revealed that Kieran's friend and Toby's younger brother Sean Gilroy accidentally led Gabby to her death, and killed Bronte when he realised that she was about to discover the truth about what happened. Sean had been in the caves with Gabby, who had been looking for Kieran in the hopes that he would buy her alcohol, and the pair had scratched their names into the stones - which Bronte had later found during her investigation.

15 years ago, Sean had kissed Gabby in the caves, but she awkwardly rejected his advances and he rushed out of the caves, leaving her struggling to follow him as the tide rushed in, eventually becoming lost and drowning. Sean realised that he has left her trapped in the caves but never told anyone except his father, who had just lost his other son Toby, and convinced him to lie about her disappearance.

Bronte was friendly with Sean, and the pair spent time on the beach when Bronte innocuously discussed her discovery about the hidden cave with him. This leads him to panic as he tried to grab her camera and delete the photos, and ended up attacking and killing her. After admitting this to Kieran in the caves, Sean tries to kill Kieran, with the pair fighting before the police arrive.

Kieran survives the attack and Sean is taken into custody. Kieran reconciles with Mia and the pair agree to stay and help out his parents as they move away from the island for a new start.