Lodged in the memory of psychologist Dr. Jan Ilhan Kizilhan are the stories of 1,400 girls and women who were once enslaved by ISIS.

The German trauma expert personally interviewed each of them, hearing countless stories of torture and rape. It was, by any measure, a grim and daunting undertaking.

All were Yazidis, a long-persecuted minority. One of the youngest was just eight years old.

"She was, for 10 months, in the hands of the [Islamic State in Iraq and Syria] and was raped hundreds of times," said Kizilhan, 51, a German psychologist and professor with Kurdish roots.

But he couldn't help all the women.

His agonizing task was to assist German officials who travelled with him to northern Iraq to choose which of the women would have the life-altering opportunity to move to Germany for treatment.

Psychotherapy means to give the feeling "yes, we have some cruel, evil persons, but the world is not all evil." - Dr. Jan Ilhan Kizilhan

Even as the rest of Germany grappled with accommodating a million asylum seekers in 2015, the government of Baden-Wurttemberg state had unilaterally committed to bringing traumatized Yazidi women and providing them with therapy and housing.

Under a special program, several hundred women and their families — 1,100 people in all — were ultimately airlifted over a year for a rare chance at recovery from hellish post-traumatic stress disorder (PTSD).

They live in more than 20 secret shelters across the state.

German psychologist Jan Ilhan Kizilhan travelled to camps in northern Iraq to choose which victims of torture and rape would have the life-altering opportunity to move to Germany for treatment. 'In Germany, they have security. We can give them orientation and stabilization,' he says. (Nahlah Ayed/CBC)

As he's taken on the role of therapist to many of them now, Kizilhan's task has only grown: not just helping them overcome deep trauma but also restoring the women's faith in humanity.

"In this case," he explained, "people lost their trust in humanity, and psychotherapy means to give the feeling 'yes, we have some cruel, evil persons, but the world is not all evil.'"

Unsurprisingly, that is a hard sell among the women.

Ask Farida Khalaf. She was a schoolgirl when ISIS fighters descended on her village on Aug. 15, 2013. They killed the men and took the women away, the younger among them to be bought and sold and appallingly abused.

In the process Khalaf lost her father, older brother, friends, and the quiet life she knew. Her four-month odyssey in the hands of several ISIS operatives took her to the heart of their territory: Raqqa, Syria. Where, despite repeatedly resisting, she was raped.

Khalaf has the name of her village, Kocho, tattooed on her hand. The village no longer exists. (Stephanie Jenzer/CBC)

"We used to wash their clothes and do everything for them. We were slaves for them," she said.

She often refused their demands and suffered for it — once beaten so badly she lost sight in one eye and couldn't walk for two months. After several attempts to escape, she made it back to northern Iraq where most of her village's survivors — including, it turned out, her little brother — were then living in refugee camps.

Khalaf, now 20, was among the women chosen to settle in Baden-Wurttemburg, with her mother and brother. They live in a secret shelter on a quiet street, embedded among other nondescript German homes.

No longer exists

When we visited (on condition its location be kept secret), the home was buzzing with the sounds of lunch preparations and children playing.

Khalaf's clinical retelling of a story that involved several attempts at suicide is devoid of emotion — until she speaks of home, a village that no longer exists.

Its name, Kocho, is tattooed on her hand.

"Even now when I try, I can't smile with my whole heart," she said in an interview.

"They raped us, they killed our men, and did all that only because we are Yazidis."

Demanded conversion

Yazidis are ethnic Kurds living mostly in northern Iraq. Their religion borrows elements of Christianity, Islam and Zoroastrianism.

ISIS extremists saw Yazidis as devil worshippers, and when they invaded, they demanded the Yazidis convert. The Yazidis refused. Thousands were killed and displaced, prompting an international bombing campaign that has yet to entirely stamp out ISIS.

In acts of symbolic support, the UN and recently Canada, declared the events acts of genocide. Canada committed to taking in some of the traumatized women, but Ottawa has yet to announce details.

Khalaf's keeps photos of family and friends, many of whom she has lost. 'Even now when I try, I can't smile with my whole heart,' she says. (Stephanie Jenzer/CBC)

There are estimates that as many as 3,400 Yazidi women remain in ISIS captivity. Hundreds more languish in refugee camps with the stigma of having been enslaved — and without psychological treatment.

"I myself documented about 60 cases of women who committed suicide," said Kizilhan, who spent 20 years researching in Northern Iraq.

"We shouldn't forget they belong to a patriarchal society: cases of honour and dishonour, and they will not have the feeling [of being] accepted by this society."

Despite that, several survivors now in Germany, including Khalaf, are telling their stories publicly in an effort to help save some of those left behind.

Nadia Murad has called on Canada to take in as many women and families possible. (Nahlah Ayed/CBC)

Nadia Murad, one of the most outspoken, called on Canada to take in as many women and families possible, to help build a sustainable community.

"It is unacceptable for a woman to be rescued from captivity from ISIS to come and not have a place to live, to be put in refugee camps," she said in an interview.

Those refugee camps are where Kizilhan's original, agonizing interviews took place.

The women had to meet three criteria:

They had once been held by ISIS.

They suffered psychological and medical consequences.

The state had the know-how to treat them.

Part of the state's plan included training psychologists and interpreters. But how can anyone overcome such deep trauma? Are the women treatable?

Kizilhan says yes — but only if they can leave the camps of northern Iraq behind.

Kizilhan interviews a Yazidi refugee. 'They should know that they are not alone,' he says. (Courtesy Sonderkontingent Baden-Württemberg)

"In Germany they have security. We can give them orientation and stabilization … and if you don't have that, you can't start treatment.

"The main idea of treatment is not to [teach] them how to forget it. It's a part of their lives."

But they can be taught to overcome their trauma, he says, perhaps in as little as two to three years.

Kizilhan says they are making progress.

Khalaf is recovering and has written a book. She has learned to tell her story in German.

There hasn't been a single case of suicide among the women.

"They are motivated to survive," says Kizilhan, because they've been rescued.

"This for me, also as a psychotherapist, is very important. They should know that they are not alone … we will stand behind them."