The Thomas family arrive on Saint X for what seems like an idyllic family trip; in present day Brooklyn, Emily has a surprise encounter with someone from her past; the genesis of Gogo and Edwin's friendship.

Discovering more about what happened the night of Alison's disappearance; Alison is drawn to both Edwin and Tyler; Emily starts to dig deeper into her past; on an off-resort excursion, a tourist family stumbles across something shocking.

After the discovery of Alison's body, Gogo and Edwin become the prime suspects in her murder. In the present day New York, Emily lies to Josh and Sunita so that she can continue to follow Clive.

More about Clive's history after he left the island; Clive reluctantly begins to open up to Emily, as she continues to pursue him, much more aggressively, with Sunita's help; Alison and Edwin get closer.

Someone from his past reaches out to Clive; Tyler tries to push things with Alison; Emily and Josh's relationship is challenged as she continues to search for answers; Emily and Sunita clash over her growing obsession.

Emily can't stop thinking about the letter; the Thomas family visits Emily and Josh; more about Claire's past.