Yes, whether it's the others/walkers or the red god stuff, it's always just simmering in the background, not even as an is it / isn't it mystery, but as a rumbling unease about to what extent these things exist and to what extent they may permeate the lives of the many characters. On film you have to have Act 1 Scene 1, Int., WOMAN WITH NIPPLES STARES GLEEFULLY AT A FIRE which is never going to be quite the same.