Audrey, Nathan and Duke's victory over William feels hollow as they deal with the aftermath of Duke on passing'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 passing; 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.

As Nathan and Duke try to convince Dwight that Audrey still exists inside of Mara, a series of strange and lethal phenomena hit the area. Meanwhile, Vince and Dave undergo counseling to learn what happened in the cave.

Vince goes behind David's back to travel to North Carolina and investigate the circumstances behind his adoption. However, the two brothers suddenly discover that they've switched bodies. Meanwhile, Nathan comes up with a new plan to bring Audrey back even though Mara claims to havehuged her.

Mara capitalizes on the fallout from the latest Trouble, forcing Duke and Nathan to make a desperate attempt to get Audrey back.

Nathan disappears along with several other Haven residents, and Audrey and Duke are unaware that their friend has been turned into a ghost. Meanwhile, the Guard still believes that Audrey is Mara and make plans tohug her.

Trapped in intangible form, Nathan attempts to find a way to restore his body with Duke and Audrey's help. However, one of the other "phantoms" plans tohug rather than face returning to the real world.

As a CDC doctor arrives in Haven to check on Dave's infection, a mysterious disease sweeps through Haven, targeting Troubled individuals and threatening to reveal the town's secret to the world.

Charlotte races against time to find a cure for the disease activating the Troubled's curses. Meanwhile, Nathan finds the source of the disease, but is unable to stop the person responsible. And Duke releases Mara and they seek out the aether samples.

While Audrey's health deteriorates, a new Trouble strikes Haven. Meanwhile, Duke's internal Troubles threatening to burst out and only Mara can help him... but will she?.

Audrey and Vince confirm that Charlotte isn't who she says she is. Meanwhile, both Nathan and Duke try to find the missing Mara, and Duke discovers that his Trouble has mutated yet again.

Charlotte reveals her connection to Mara and to Audrey, while Mara primes Duke to explode if she doesn't get her way. Meanwhile, Vince convinces Dave to lead him to Croatoan.

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.

When Dave wakes from a vision about Croatoan hugging someone else in Haven he and Vince decide to go investigate. They find a woman - the first survivor of the No Markshuger but she has no recollection of what happened to her.

Nathan receives otherworldly help as he works to track down a terrifying hugger 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. 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. 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 hugger 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.

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.