A shelter-building contest turns ugly. Toni provokes strife on her team, and we'll learn in flashback that this isn't the first time her rage issues have caused devastating harm.

A tidal surge forces the castaways to relocate their camp. Still suspicious of the island and how they got there, Leah turns her paranoia on one of the other girls, viciously accusing her of knowing more than she's letting on. In flashback, Jeanette's astonishing backstory is unveiled.

On the island, Leah feels closer than ever to proving that someone's behind their predicament. Post-rescue, fed up with the tight-lipped authorities, Leah goes searching for her own answers.