On the night of April 14, 2014, Boko Haram fighters kidnapped more than 250 schoolgirls from the town of Chibok, Nigeria.
Two years later, most of the girls are still missing. Now CNN is broadcasting a video purportedly showing more than a dozen of the girls, still alive as of December.
The "proof of life" video had been shown to negotiators and some members of the government, the news network says.
NPR's Ofeibea Quist-Arcton described the back story, and the video, for our Newscast unit:
"Two years ago, 276 students were abducted from their dorms in a nighttime raid by Boko Haram fighters. Dozens managed to escape, but 219 girls are still missing and had not been heard from since.
"The video, believed to have been recorded on Christmas day last year, shows 15 girls lined up against a dirty yellow wall wearing Muslim veils and answering questions barked out by a man behind the camera.
"CNN talks to mothers weeping as they recognise their daughters. One cries out, 'My Saratu,' wailing as she reaches out as if to pluck her daughter from the computer screen."
You can watch the video on CNN's website.
The kidnapping of the Chibok girls spurred a global awareness campaign in 2014. The hashtag #BringBackOurGirls went viral.
Thousands of other children have since vanished in Nigeria and surrounding countries, according to UNICEF.
Nigeria's military claims to have saved more than 11,000 hostages in just the past two months — none of them Chibok girls.
Last month, a girl on an apparent suicide attack mission in Cameroon ran for help and surrendered to authorities, saying she was one of the Chibok girls. If true, it would be the first concrete news of the missing girls' whereabouts in months.
Boko Haram was the deadliest terrorist organization in the world in 2014, according to the Global Terrorism Index. UNICEF says the group has increasingly been using children in bombing attacks.