The scene where Diane is invaded by an invisible force and dragged up the walls was, at one time, a much darker and more aggressive sequence. It was a bit more clear that she was actually being raped by the invisible force.
The original concept begins with Diane brushing her hair in front of the mirror. At one point, she flips her hair around and finds that her newly formed grey hairs are frozen in the air. Similar to a concept from The Entity, deep, finger-like impressions press up against her jaw. The invisible force then appears to give her an uninvited kiss.
While this is going on, the stain on the bedroom wall grows, before eventually reaching a stopping point. It then begins to breathe.
Diane runs to the door, but the force closes it before she could escape. She is then violently flung onto her bed. Her robe is torn off, leaving just her nightgown. Her legs are forced open and her body is thrusting in a more than suggestive manner. She is then dragged on to the wall, according to the screenplay, “across the mandibles of the spider stain.” She is then slammed against the stain, before being dragged to the other side.
As you can tell, the original scene would have granted Poltergeist an R rating, which was not Spielberg’s intention. The scene was re-shot in a less suggestive manner.
