Ichabod Crane finds himself 250 years in the future and realises that evil accompanied him to modern-day Sleepy Hollow. Ichabod forms a bond with Detective Abbie Mills after the Headless Horseman murders the sheriff.

While still adjusting to 21st-century reality, Ichabod and Abbie continue their quest to clear up Sleepy Hollow's mysteries.

Another member of the army of evil going by the name of the Sandman tortures the people of Sleepy Hollow by infiltrating their dreams and turning them into nightmares. When he targets Abbie, she must seek out her institutionalised sister, Jenny, and face her past.

After Abbie's sister escapes from a psychiatric hospital, Ichabod helps Abbie search for her; Ichabod and Abbie learn more about the evil they are facing, including its name.

When an unidentified, sickly boy is found in town, Ichabod and Abbie learn something disturbing is going on.

When Ichabod goes missing, Abbie has a vision that the headless horseman will return to Sleepy Hollow. She turns to Henry Parrish for help.