The stranded girls grieve one of their own. Meanwhile, we learn they're not the only ones ensnared in this social experiment-it turns out there's a male control group, marooned on a different island.

The girls struggle to adjust to their new camp, while food scarcity plagues the boys. Raf gains confidence thanks to a new friendship, but flashbacks reveal the dark side of his codependent nature. Post-rescue, Leah makes an unexpected ally.

A brush with passing rattles the girls. The boys must defend themselves against a blood-thirsty predator. In a series of flashbacks about Scotty and Bo, we learn how the world has tried to grind them down, and why it's hard for them to trust the other castaways.

The boys continue to battle against the dangerous predator, and this time they plan a coordinated attack. A birthday on the girls' island puts everyone but Rachel in celebratory spirits.

Rachel seeks necessary closure, while Fatin makes an unsettling discovery in Nora's journal. Meanwhile, an incident comes to light that sends shockwaves through the boys' camp, altering their life on the island forever.

Now that they've expelled an alleged criminal from their ranks, the boys clash over how much mercy to show him.Ivan's past choices back home have impacted his life and those around him. Over on the girls' island, Leah's mind starts playing tricks on her, while Martha's past comes back to haunt her in a catastrophic way.

The girls relocate to the hot springs, but the perilous journey shatters the group and Leah is driven further into madness. The boys manage to come to a truce, but it's upended when troubling secrets about their most controversial member come to light.

Each girl on the island is engaged in some kind of struggle to find peace and the truth. Meanwhile, the boys must decide whether or not to attempt a dangerous trip.