Based on the true events of the only case in US History where a spirit caused the death of a man.

Richard Powell: [of Betsy] Can she love me?
Lucy Bell: She will.
Richard Powell: This... entity... do you believe that it can read your mind?
John Bell: No. But I do believe that it can hear our conversations, that's how it knows our every move.
Richard Powell: But it is only present on this property!
[Richard raises his eyebrows, suggesting that if they leave without saying a thing, the entity probably wouldn't know, or follow]
John Bell: You were always a sound sleeper.