When Sheriff Corbin's son returns from war, his strange behaviour has Abbie and Ichabod questioning his intentions.
Crane and Abbie are forced to face their pasts in surprising ways when a new form of evil is unleashed.
Fear is rampant in Sleepy Hollow when Pandora releases an artefact from her box that can transform the townsfolk into terrifying creatures.
As a flu epidemic threatens the US, Federal Agent Brad Wolgast is tasked with bringing in the experiment's latest chosen test subject, where his loyalties to Project NOAH are tested.
Sharpe has an important realisation that will affect her career. Meanwhile, Max and Reynolds take on uncharted waters when a young patient comes to New Amsterdam with symptoms of a heart attack.