After the deaths of Henry and Katrina, Ichabod goes to find himself while Abbie joins the FBI. However, the discovery of an ancient tablet brings Ichabod back to the U.S. and the Witnesses discover that the Second Tribulation may be starting.
When Pandora uses her powers to unleash a new form of evil, Abbie and Crane are forced to face their pasts in unexpected ways.
Pandora resurrects an ancient evil from Ichabod's past to terrorize Sleepy Hollow. Meanwhile, Jenny takes Joe along to track down the Shard's thief, and Daniel offers to clear the air with Abbie.
Pandora summons a new monster to terrorize Sleepy Hollow: the Abyzou, which steals the souls of children who are losing their teeth. Meanwhile, Abbie tells Jenn that she has found their father, and Ichabod goes to the dentist.
Pandora resurrects Ichabod's nemesis General Howe to lead an army of undead warriors on Sleepy Hollow. To stop Howe, the Witnesses need to find his tomb and turn to Brennan and Booth for help.
Pandora unleashes a monster that triggers waves of paranoia in its victims, followed by death. While Ichabod and Abbie hunt it down, Joe meets with Atticus to find out more about his father.
Daniel leaves Abbie in charge while he goes to DC on the Nevins case. Meanwhile, Atticus summons three berserkers to recover the energy from the Shard of Anubis, and Ichabod, Abbie, and Joe close ranks to protect Abbie's sister.
Pandora nurses the Hidden One back to health, but he requires the Eye to regain his energies... and the Eye rests within Jenny. Meanwhile, Abbie resigns from the FBI so that she's free to go after the Witnesses' enemies with Joe and Ichabod.
A month after Abbie's disappearance, Ichabod continues the search for his partner. However, he sets loose an unspeakable evil by mistake. meanwhile, Jenny and Joe go after an occult map that they hope will lead them to Abbie.
Crane and Sophie attempt to deal with a supernatural force that has been targeting Sleepy Hollow residents as Pandora and the Hidden One increases in strength. Jenny looks into Abbie's disappearance.