When Jan Broberg was just 12 years old, she was abducted and repeatedly raped by the 40-year-old best friend of her family, who convinced her aliens wanted her to have a child with him.

Her parents were so brainwashed by Robert “B” Berchtold, who had been molesting their child for months, they did not believe he had kidnapped her, and didn’t report her missing for days.

Even after he asked for their permission to marry their daughter and was tracked down to Mexico, they signed affidavits to prevent the pursuit of a prosecution against him. The case went ahead anyway, and Berchtold was sentenced to five years. Later, his sentence was reduced and he spent just 45 days in prison.

And the story gets even more extraordinary. After his release, Jan’s attacker abducted her again from her bedroom, staging it to look like she’d run away and insisting in phone calls to her parents that he had spoken to her but not seen her.

“I was a very tiny little girl, I think sometimes people don’t get that,” Jan, now 56, tells News.com.au. “I didn’t start into puberty until I was 17. I was 95 pounds, 5 feet tall when I graduated from high school and I didn’t start my period until the summer afterward. So I think I didn’t fully recognize all these parts and people until I was in my 20s.

“I went through a period of time when I was angry, just in general about a lot of different things, but I never felt like I was blaming any party except him, because he was a master manipulator of all of them, of everybody, he orchestrated it so perfectly.”

Jan’s parents and their community in Idaho in the early 1970s were completely under the pedophile’s spell.

Berchtold lured both Bob and Mary Ann Broberg — members of the Church of the Latter Day Saints — into separate sexual encounters, playing on their vulnerability and guilt to achieve his sick aims.

He was obsessed with Jan. “He did give special attention to Jan that annoyed both Bob and I,” says Mary Ann in the powerful Netflix documentary now lighting up the internet, “Abducted in Plain Sight.”

“His fascination with Jan was a little disturbing.”

Berchtold told Jan’s parents he had been abused by an aunt as a child, and as part of his therapy, he needed to spend time with their daughters. For six months, he slept in Jan’s bed four days a week, playing “therapy tapes” and molesting her as she slept, drugged on sleeping pills.

When he asked to take the young girl to see horses at a local stable in October 1974, her mother agreed. Berchtold gave Jan an “allergy pill” and she passed out. When she woke, she was in a motorhome, with an alien voice telling her from a recorder that she was part-alien, and it was her “mission” to have a child.

“I believed it absolutely,” she says in the documentary. “When you combine being isolated and completely afraid, you can pretty much get someone to do or believe anything.”

Jan says she completely trusted and loved him. Meanwhile, the Brobergs and their friends were utterly convinced Berchtold would never harm Jan.

A neighbor who tells the documentary-makers he felt uncomfortable about the friendship, and didn’t want anything to do with Berchtold, even wrote Berchtold a letter of recommendation to help him adopt a girl a year earlier. The adoption never happened.

When Bob and Mary Ann finally, reluctantly, reported their daughter missing, police found his car with the window smashed from the inside, and blood on it — a cover story he had created.

Berchtold had taken Jan to Mexico, where he spent five weeks abusing her and even married her, since the legal age of marriage in Mexico was just 12. He then called his brother Joe and asked him to call her parents and ask for their written permission to marry her in the United States, and then he would return her.

Joe says in the documentary that he had always known his brother was a pedophile, who had attempted a relationship with their half-sister years earlier. He contacted the FBI and Berchtold was caught.

But, incredibly, in 1976, he abducted Jan for a second time.

Jan, who wrote a book about the experience with her mother and is now an actress as well as an advocate, estimates he tried to abuse her around 200 times. “There’s a shame in being sexually violated, that you somehow did something,” she tells News.com.au. “How could I be so stupid? Did I do something wrong?”

Choking back tears, she describes in the documentary how she would stare through a skylight at the leaves on a tree to help her survive the rapes.

Her family said they had no concept of what a child abuser was. Everyone failed to see what was going on under their own eyes.

Incredibly, Berchtold re-emerged to refute their 2004 book, even filing a lawsuit to prevent its release and turned up at one of her speaking conferences with a gun. His goal was to see Jan again, and they came face-to-face in court after almost 30 years after. Jan learned he had been living just an hour away from her. She says her “mother tiger” came out, and she felt pure rage for the young girl she had been.

“It was like a complete moment of healing, of knowing who I am, of coming into my own power of knowing exactly why I was telling my story, and it was, as I said in the courtroom, to protect other children from monsters like you.”

A year later, Berchtold took his own life.

Jan and director Skye Borgman say they have been “overwhelmed” by the flood of responses from the public, many of them blaming Jan’s parents for her fate.

“My parents were manipulated and they were naive, they were also manipulated by a master sociopath that was a criminal,” Jan tells News.com.au. “Somebody doesn’t just come in and manipulate and brainwash the child, they work on an entire system of people around the child they become the best friend of the mother, the father, the neighborhood and everybody loved this guy.”

Berchtold groomed Jan and the people around her for seven years, and Jan says it is hard to hear people attack her parents. “Would I have even had a chance of surviving without the amazing, wonderful parents that I have?” says Jan. “No.”

“The bigger message is somebody is assaulting a child you know right now and you just don’t know it because it’s somebody you love and trust. So wake up. See something you wouldn’t have seen before seeing this documentary.”

Bob died in November, and Jan is grateful he is not here to experience what Borgman calls the “pretty violent backlash.” Mary Ann retrained to become a social worker and places children in foster care and lobbied for Idaho to sign up to a register for exploited and missing children. “I think part of that was to overcome her own guilt and shame at not having seen clearly,” says Jan. “But it’s not uncommon.”

It is hard, as a viewer, not to judge the young girl’s parents for closing their eyes to what was happening to their daughter. Borgman says it is hard to understand brainwashing if it hasn’t happened to you, and she is fascinated by how a perpetrator uses “shame and denial” to get people to do what he wants. She was moved by Bob’s emotional, shocking confession in one difficult scene of how he had masturbated Berchtold in a car.

“Not many people have talked about Bob and Mary Ann’s bravery and that is something I have always been struck with,” she adds. “If something like this had happened to me I’m not sure I would ever talk about it.

“And I don’t think there is any reason anybody would talk about it, except that they want their story to be out there, want people to see something in the story that hits very close to home, so they can move forward and hopefully protect children.”

“Abducted in Plain Sight” is out now on Netflix.