Abbie and Ichabod look for clues to stop the evil in town; Abbie receives an unexpected visit from Andy Brooks.
Ichabod and Abbie travel to purgatory as the battle between good and evil comes to a head, changing Sleepy Hollow forever.
Abbie and Ichabod plot to resurrect a monster created by Benjamin Franklin as part of a plan to rescue Katrina; Frank faces the consequences of revealing the truth about his encounter; Jenny clashes with the new sheriff.
Abbie and Ichabod seek out the sword of Methuselah to kill Moloch before the Headless Horseman can stop them.
A woman from Ichabod's past arrives in town, undead and aiming to harm anyone in her path; Katrina and Ichabod learn disturbing things about each other; Abbie has flirtatious encounters.