How many endings are there and what are the differences between them?
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There are three endings; the theatrical ending, the unrated ending and an ending that was, apparently, only seen once at a Film Festival.
The theatrical ending (suggested by director Stephen Speilberg) has Katie awaken to once again stare at a sleeping Micah for several hours. She then goes downstairs into complete darkness and suddenly starts screaming for no apparent reason. Micah hears her and wakes up, running to her aid. The camera can only see the bedroom and dark hallway as it records what sounds like a struggle between Micah, Katie and whatever else is downstairs with them. Micah and Katie's screams suddenly stop, and the brief silence is followed by the sound of heavy footsteps coming up the stairs. Micah's body is suddenly hurtled at the camera, knocking it over. Katie appears in the doorway, her clothing covered in blood. She crouches down and starts sniffing at Micah's lifeless body, then smiles at the camera before lunging toward it and the screen smash cuts to black and the credits roll.
In the ending of the unrated version (which is the original cut of the film and available on DVD/Blu-ray), Katie returns to the bedroom after the struggle heard downstairs, wielding a knife with blood on her tank top. She then sits next to the bed and rocks back and forth in a catatonic state throughout the remainder of the following day. Her friend Amber calls the house, and later arrives, discovering Micah's body downstairs. When police officers arrive, Katie comes out of her catatonic state and approaches them asking for Micah. The officers instruct her to drop the knife, but shoot her after being startled by a door suddenly slamming behind them. The movie ends with audio of the police discovering the camera as the credits roll.
The Film Festival ending involves Katie returning to the bedroom with the knife (just like she did in the unrated ending) and slitting her own throat in view of the camera. The credits then roll.
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