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

When Audrey and dozens of Haven citizens are affected by a mysterious illness, the symptoms threaten to expose Haven’s secrets to a dangerous newcomer.

Haven’s heroes are torn over how to deal with an inquisitive CDC scientist, who could expose the secret of the troubles to the world, but may be hiding her own dark agenda.

Duke’s roiling troubles and a new threat to Audrey force them each to seek the help of potentially dangerous allies.

When a trouble drives Haven’s citizens to pursue their more primal desires, it takes everyone to keep Haven from coming unglued-distracting them from the menacing storm that is brewing.

As Mara'a endgame becomes clear, Nathan and Audrey pursue a plan to stop her once and for all.

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.

Desperate conditions in Haven lead to a terrified population that's difficult for Dwight to maintain control over; at the same time, Nathan assembles a task force to restore power to the town; and Audrey tries to put an end to the trouble once and for all.

Dwight and Charlotte work to clear Nathan's name when the citizens of Haven put the lawman on trial. Hoping to buy them time, the brothers Teagues moderate the courtroom proceedings, while Audrey continues her quest to solve the darkness troubles.

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.