WHAT EVER HAPPENED TO THE NIGERIAN GIRLS KIDNAPPED BY BOKO HARAM?

THIS SUNDAY ON "60 MINUTES": SOME OF THE TEENS KIDNAPPED BY THE ISLAMIST MILITANTS ARE FREE AND BACK IN SCHOOL, PURSUING THE EDUCATION THEIR CAPTORS WANTED TO DENY THEM

Their story went viral and captivated the world: 276 schoolgirls kidnapped from their school in Nigeria and taken into the forest by the Islamist militant group Boko Haram. They endured beatings and bombing attacks and had to eat grass to thwart starvation. Three years after their kidnapping, the Nigerian government was able to free 103 of them. They are traumatized from their ordeal, but undaunted in their pursuit of the education that made them targets for their captors in 2014. Lesley Stahl gains rare access to some of the young women at their school for a 60 MINUTES report to be broadcast Sunday, Feb. 17 (7:00-8:00 PM, ET/PT) on the CBS Television Network.

They are now in their 20s and once again can sing together the Christian songs they grew up with but could never sing above a whisper in captivity. Rebecca, one of the "Chibok Girls," so named for their hometown, tells Stahl, "[Boko Haram said] if you didn't convert to Islam, you wouldn't get home alive."

Stahl visited a group of the women in a special boarding school they attend to continue their studies in preparation for college and receive much-needed help from therapist Somiari Demm. The process of balancing the learning with the healing is a delicate one. "I think at times, we need to kind of scale it back. Trauma really changes the brain, whether memory, cognition, recall, retrieval," says Demm. "We have to meet them where they are. If not, all we're doing is making the situation worse."

Keeping the women physically together after their captivity is central to their caretakers' strategy of healing and educating them. They took care of each other in captivity, right from the first night. Grace badly injured her leg when she was captured. "They are taking care of me. They are fetching water. They are washing me, my clothes, and everything," Grace recalls. Her friend Aisha tells Stahl, "We are worried about her leg. We don't have anybody there who will take care of her. Only us."

Says Demm, "They just had an unbelievable bond, and an attachment to each other."

Boko Haram roughly translates to "western education is forbidden." But even after their kidnapping, the women are determined to finish their schooling. Rebecca tells Stahl, "Even what happened with me will not stop me doing what I already desire in my mind."

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