BLAME it on Twilight.
Author Seth Grahame-Smith seized upon the idea for Abraham Lincoln: Vampire Hunter during a promotional book tour for his 2009 parody Pride And Prejudice And Zombies.
It was the year marking the bicentenary of Lincoln's birth and authors Stephenie Meyer and Charlaine Harris were riding high in the best-seller lists with their Twilight and The Southern Vampire Mysteries books.
Seeing displays for these two disparate subjects side by side, Grahame-Smith decided to rewrite the personal history of the 16th president of the United States and re-imagine the Civil War as a fight between the Union and the vampire-riddled Confederacy.
Balletic, gravity-defying action sequences arc the blood of the undead at the camera in glorious 3D as the script, adapted by Grahame-Smith himself, covers 45 years in Lincoln's life, culminating in The Battle of Gettysburg.
As a boy in Pigeon Creek, Indiana, Abraham Lincoln (Benjamin Walker) witnesses his beloved mother Nancy (Robin McLeavy) fall victim to vampire Jack Barts (Marton Csokas), who lives among the humans as a slave trader.
Abraham swears revenge and is tutored in the finer points of vampire extermination by enigmatic mentor Henry Sturgess (Dominic Cooper), who despatches his pupil to Springfield in 1837 to hunt down the fanged fiends.
Gradually, Abraham embarks on a political course as a fervent abolitionist, using words as weapons rather than his trusty axe.
His words fall on deaf ears and Abraham marries Mary Todd (Mary Elizabeth …