10 Terrifying Movie Monsters That Barely Appear

In Robert Wise's adaptation of Shirley Jackson's The Haunting of Hill House, a team of paranormal investigators spends the night in an eerie mansion to verify whether it's occupied by ghosts... but by the end, that question is left unanswered. 

Spirits are never directly seen, so it's hard to tell whether the ominous occurrences in the house are supernatural in origin. The lead character, Eleanor, bears witness to peculiar sounds, cold spots, and pounding on the doors, all indicating the building is definitely haunted. On the other hand, much of the story is seen through Eleanor's perspective, who comes across as an unreliable narrator due to her fragile emotional state. As a result, what Eleanor claims to see, hear, and experience may only exist in her mind.

This ambiguity keeps everyone on their toes every single time something creepy happens. Sure, it'd be frightening if the ghosts' presence was undeniable, but at least there would be some sense of closure, knowing they were real all along. But since the spectres' existence is left uncertain, that fear of the unknown is likely to stay with viewers long after the credits roll.