SOUTHERN TURKEY — After driving around a small town here for about 15 minutes to make sure we weren't being followed, we were finally taken to a safe house where we waited for three Syrian women to arrive.
They walked in together, dressed in the most conservative form of Islamic clothing, which covered everything but their eyes.
It was hot and stuffy in the small apartment. The owner didn’t want to open the windows, fearing his neighbors might see what was going on.
The women were members of ISIS’s feared morality police. They had defected and fled to Turkey, but they’re not out of danger here. ISIS, which has informants on both sides of the border, is not a group that treats quitters kindly, especially when they talk to foreign journalists.
Dua, short with strong shoulders and stocky build, says she became a believer in the ISIS ideology when she married one of the group's fighters in Raqqa. He was from Saudi Arabia. Like the other two women interviewed by NBC News, Dua only wanted to be identified by a nickname.
"A member of the group (ISIS), a Saudi, came and asked for my hand and I married him," said Dua. "I was married for six months, then he died in a suicide attack."
Her family, Dua says, forced her to marry the Saudi man. They were poor and he offered them $2,500. Dua says her family needed the money and was too scared to refuse an ISIS militant.
While married, Dua became an enforcer in the female morality police.
"They would cut off heads, and put the heads on the streets, or display bodies where everyone, even children, can see them. It was too much"
"I would tour the markets, take part in raids, and take women who were violating the dress code to the headquarters," she said. "First we’d warn them, but if they continued, they would be lashed. Twenty, or 40 lashes for her, and the man responsible for her."
Dua admits she sometimes did the lashing herself, and described what she called a typical case.
"There was a woman who violated her dress code; her cloak had a design on it. They brought her to me and I lashed her 40 times," she said.
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Flourishes of any kind on women’s clothing are forbidden under ISIS’s rule.
"When they told her to come, she tried not to, to escape her punishment. So they increased her sentence. It was supposed to be 20 (lashes), but since she wouldn’t come, I whipped her 40 times," Dua continued, saying she used a length of cable to whip the woman.
"She was screaming and crying and all of that, but this was supposed to be a lesson, the last time ... She’d been warned before, but kept violating," she said.
Did Dua feel bad about it?
"There had been many cases before her, so we were used to it," she said.
Dua's colleague in the female morality police, known by ISIS as the al-Khansaa Brigade, was Umm Asma. She has a slender figure and light brown eyes which before our interview she framed with thick black mascara. It’s part of a new look for Umm Asma, and part of her new way of thinking. When she was with the al-Khansaa Brigade, Umm Asma detained women wearing even the slightest trace of cosmetics.
Umm Asma, who speaks broken English, was part of the ISIS welcoming party. Her primary job was to receive foreign women and show them the ropes.
"Mostly they were from Germany, France and the U.K. — many countries," she said. "A translator would talk the women, and say, 'welcome. Come to the car. We’re going to the headquarters to give you Islamic dress and show you how to wear it. Then we’ll take you to your post and God willing you will be happy there.'"
Umm Asma says the foreign women were happy when they arrived in Syria, excited to join what they believed to be an Islamic paradise on earth where only Allah’s law was enforced.
"They came for the love of the Islamic State and the love of religion of Islam," she said, explaining that ISIS uses female recruiters to convince women to join through social media.
The third women we interviewed, Umm Ous, said ISIS gave members of the al-Khansaa Brigade military training, but that focused more on the foreign recruits.
"The training lasted a month," she said. "Fifteen days of religious training, which was done in the mosques or in the headquarters — there is no specific place. Then, the military training on how to use weapons like the American Glock (pistol) ... They showed us how to use them, but the foreign women, they taught them to use weapons for attacks."
"A member of the group, a Saudi, came and asked for my hand and I married him ... I was married for six months, then he died in a suicide attack."
She said she had no information about any current plots inside or outside Syria.
The three women told NBC News they were all initially happy to be part of ISIS, but that over time the group’s brutality revolted them.
"They would cut off heads, and put the heads on the streets, or display bodies where everyone, even children, can see them. It was too much," Dua said.
To listen to Umm Asma, Raqqa under ISIS sounds like the set of a horror movie.
"For example, they displayed bodies," she said. "A body would stay hung on the street, so you’d have to pass it ... it smelled and dogs would eat it, everything happened. You would see heads on the ground. It was disgusting," she said.
The three women say they now regret joining ISIS, but believe they have been so tainted by their association with the group that it will be difficult for them to rebuild their lives.
"I can never go back to Raqqa. Even if ISIS is thrown out, because so many people have suffered, they won’t accept me back," Dua said.
For now, the women live in hiding in Turkey, unsure of what their futures hold.
Richard Engel has been NBC News' chief foreign correspondent since 2008.