Scene that makes no sense

I think it's time to discuss the scene I always thought never made much sense. Given the internal logic of the movie, of course, since a film about atomic vampires already fails the logic of credulity. :) But, even within the film itself, I've always found one scene to not make a whole lot of sense. That scene is the one where Sheila hears a noise upstairs, goes up, and finds a bloody knife imbedded in her latest sculpture.


This implies that there's a vampire in the house already. So, why didn't it get Sheila then and there? In fact, why did 2 vampires wait for another victim to show up before attacking? Where did the vampire go after stabbing the sculpture? Where did the blood come from? Plus, surely, a vampire wouldn't leave behind that much.


I do have one explanation that can pass a "logic" test. That what we saw wasn't real. It was a vision of disaster, like the one she talked about when Sheila first shows up in the movie. So, the scene was seen from her POV.


Comments?