Insidious

"This entity is very powerful. It's a spirit who used to live in this building a long time ago. It's been alone for a long time. But she's making it stronger. It's feeding on her life force. Usually, entities of this type, living in the dark, they want to possess the bodies of the living so that they can leave the dark and return to life. But there's another kind of a spirit. It's an even worse kind. One that does not wanna leave the dark, that wants the souls of the living to join it in the shadows. She's only half a person right now. After the accident, it got half her soul. It needs all of it. And if we don't hurry, it's going to get it."