But suspense presupposes uncertainty. No matter how nightmarish the situation, real suspense is impossible when we know in advance that the protagonist will prevail (as we would if Woolrich had used series characters) or will be destroyed. This is why, despite his congenital pessimism, Woolrich manages any number of times to squeeze out an upbeat resolution. Precisely because we can never know whether a particular novel or story will be light or dark, allegre or noir, his work remains hauntingly suspenseful.(Introduction)