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 struggles to maintain order when Duke's trouble wreaks havoc around town; at the same time, Audrey and Charlotte work together to drive away a mysterious fog that has everyone trapped in 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 and Dwight race to rescue Audrey from Croatoan, but the consequences of Duke's dark destiny wreak havoc on their plans. Meanwhile, Vince contemplates an unusual sacrifice.