The Seekers follow a monster to Haven; their presence threatens to reveal the town's troubles to the entire world.

Audrey must call in outside help as she is no longer immune to the troubles and Nathan may be lost forever.

Dwight and Charlotte work on a way to free Audrey from the Sandman's stasis before he can trap her in his mind forever; at the same time, Duke tries to help Darkside Seeker Seth Byrne recover his memories of Haven.

Charlotte and Audrey work on their new plan to eliminate the troubles, but something seems to be thwarting their attempts, and it's up to Nathan and Dwight to get to the bottom of it. Meanwhile, the Teagues brothers search for the mysterious serial killer who's stalking the streets of Haven.

Nathan receives otherworldly help as he works to track down a terrifying killer; and Duke reaches a crossroads after he has an alarming vision of Haven's future.

Nathan struggles to return to Haven as Dwight reconsiders his future in the series finale, which also finds Audrey coming to a terrifying decision about how she might finally save the town from Croatoan.