In Chapter I of Dracula, Bram Stoker writes in Jonathan Harker's Journal:
"One of my companions whispered to another the line from Burger's 'Lenore:' - "Denn die Todten reiten Schnell." ("For the dead travel fast.")
Stoker is quoting Gottfried August Burger's macabre folk ballad, Lenora (or Lenore), which includes the refrain "the dead ride quick." Lenora tells the story of a soldier, William (or is it Death?), who arrives on horseback in the dead of night to retrieve his lover, Lenora. There are several interesting translations of the ballad from German to English.
The dead travel fast; the dead ride quick; the dead pass swiftly; the dead drive fast ...
All in all, the dead aren't slow ...
Stoker also refers to the line in Dracula's Guest (published posthumously in 1914):
"On the top of the tomb, seemingly driven through the solid marble - for the structure was composed of a few vast blocks of stone - was a great iron spike or stake. On the back I saw, graven in Great Russian letters:
The dead travel fast."