When shrewd and confident FBI Special Agent Audrey Parker arrives in the small town of Haven she soon finds herself caught up with the return of The Troubles, a plague of supernatural afflictions that occurred in the town at least once before. If that was not enough to draw her in, she also finds a link that may lead her to the mother she has never known.
Audrey, Nathan and Duke's victory over William feels hollow as they deal with the aftermath of Duke on death's door, Mara in control of Audrey's body, and a strange trouble supernaturally silencing citizens all over town.
Duke struggles to accept Jennifer's death; Nathan searches for some shred of Audrey in Mara's cruel personality; Dwight shoulders the heavy burden of holding Haven together.
Nathan makes a desperate play to protect Mara from the furious citizens of Haven, leaving Dwight and Duke to deal with a deadly trouble that threatens to burn the town to the ground.
Dwight and Nathan clash over what to do about Mara; Dwight wants her to end the troubles at any cost, but Nathan is convinced that Audrey is in there.
When Vince and Dave travel to North Carolina, their probing of Dave's past uncovers a body-swapping problem back in Haven.
Mara capitalizes on the latest crisis, forcing Duke and Nathan to roll the dice to get Audrey back in a dangerous gamble.
A paranormal trouble tears Audrey and Nathan apart just after they were reunited.
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.
Nathan and Vince travel back to the year 1983 in order to discover Croatoan's origins in Haven; at the same time, Duke finds himself in grave danger after being apprehended by a mysterious foe.
Nathan encounters an old adversary after entering the terrible Void; Audrey and Duke deal with the threat of a newly troubled person who wants revenge; at the same time, Dwight tries to help Vince free Dave from Croatoan's grip.
While Duke tries to convince Hallie to reopen the thinny, Nathan tries to escape from the Void where he and William are trapped. Meanwhile, Dave must consider making the ultimate sacrifice to stop Croatoan.
Plans for building a new barn are complicated when an old trouble brings the Haven Police Station to life. It's up to Audrey and Nathan to find a way to regain control, but their efforts are hampered when a mysterious killer leaves a wake of bodies right under their noses.
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.
Hope of ending the troubles begins to fade as the heroes struggle to rebuild the Barn in the face of mounting obstacles. And while Dwight is tempted by a surprise gift, Nathan finds himself considering a devastating sacrifice.