I wonder if Arsem Ibraham's mother would recognise him now.
His hair has grown long and tumbles around his shoulders.
His forehead is a rash of angry adolescent skin above soft brown eyes.
He is no longer a boy; not quite a man.
For three years the only family he has known are soldiers of the so-called Islamic State.
They taught him to hate and to kill.
"They trained me for six months in a military camp," he tells me. "How to use automatic rifles and rocket launchers. They told us we must kill the Kurds, the infidels. The Free Syrian Army – they are infidels. We must kill them too."
Arsem is a Yazidi and had just turned 13 when Isis attacked his people on Sinjar Mountain.
They separated the boys and the women from the men.
"Then they blindfolded me but I could still hear the shooting. Three shots into one man," he remembers.
The boys were taken to Raqqa and joined what Isis calls its Caliphate Cubs.
They trained him to use a rocket launcher and automatic rifles.
And they began the process that would make some of them suicide bombers.
He says the bravest and the best were promised the ultimate mission.
"Every day after training we were shown the latest videos of suicide attacks. We were told: 'Look up to these brothers.'"
In other circumstances we would call this grooming.
"We were told whoever blows themselves up will go to heaven. There will be 70 virgins waiting for us and rivers of wine."
There was talk of sending some of the boys through Turkey to attack in Europe.
"They said: 'Don’t worry. We will do a big, big attack in Europe. Isis is working hard on that.'"
It was, in the end, just talk.
As the coalition tightened its grip on Raqqa, Arsem was captured again. This time by Kurds. This time he will be set free.
I ask him what he will tell his mother when he sees her again.
For the first and only time he smiles.
"I will tell her I have been born again," he says.