George A. Romero said:
Francine: They're still here.
Stephen: They're after us. They know we're still in here.
Peter: They're after the place. They don't know why, they just remember. Remember that they want to be in here.
Francine: What the hell are they?
Peter: They're us, that's all, when there's no more room in Hell.
Stephen: What?
Peter: Something my granddad used to tell us. You know Macumba? Voodoo. My granddad was a priest in Trinidad. He used to tell us, "When there's no more room in Hell, the Dead will walk the Earth."