I disagree about the ending. While the soap opera fan in us would love to see the story play out in a serial fashion, there is no escape for Martha. She is haunted. She is traumatized. And while she may go on with her life, she'll never escape the grasp the cult has on her and her psyche. She's fucked. Unless she fully accepts massive psychological treatment, she will continue to be a victim, being stalked by visions of her past.

that's how i interpreted and accepted the ending.