After a fight the night before, Erin fails to show up for the flight leaving Lori to travel to the island alone. Meanwhile, in the present day, Erin's refusal to accept the truth of her sister's death leads her to a startling new clue.

Having crash-landed on a desert island, Lori and the other passengers fight to stay alive as peril lurks at every corner. As her search for the pilot leads her back to Fiji, Erin forms an unlikely allegiance with his daughter.

With all hope seemingly lost, Lori turns to increasingly desperate measures to survive. Erin's discoveries reveal a far more complicated mystery that only leads her further from the truth.

When both sisters uncover startling secrets about one of the survivors, they are dragged further into danger. A race against time begins in order to save innocent lives on the island.

As Erin gets closer to the truth of her sister's fate, a final showdown awaits her on the island. Some secrets are worth killing for and not everyone will escape the island alive.