September 2016: Stacey Dooley embeds herself on the frontline with the extraordinary all-female Yazidi battalion, who are fuelled to take revenge against the so-called Islamic State.

As the battle to take Mosul from Isis advances in Northern Iraq, in this extraordinary film for BBC Three, Stacey finds these young women's lives have been transformed by a desire to avenge their loved ones who were murdered by Isis.

In 2014, 50,000 Yazidis fled their ancestral lands in northern Iraq to Mount Sinjar, away from the advance of Isis. Without food and water, thousands died on the mountain and the ones left behind were massacred or captured.

Two years after the genocide, Stacey spends two weeks with this battalion of brave young women. Formed by a renowned Yazidi singer, they have transformed into brave fighters. Many of them have escaped the incomprehensible horrors of Isis and are determined to rescue Yazidi women still under Isis control. These female fighters strike fear into the heart of the jihadists as they believe if they are killed by a woman they will not make it to the heavenly afterlife.

Stacey meets cadets at their training camp as they prepare to join the battalion, before journeying with them to the front line as they prepare to fight.

These women share with Stacey happy memories of their previous lives, and then the unimaginable trauma they have endured at the hands of Isis. With extraordinary access, Stacey Dooley for BBC Three meets the young women seeking to avenge their sisters on the frontline with Isis.