Khalid looks younger than his 15 years. I'm sat opposite him in a tent in Za'atari camp. The sun is beating down on the tent and there are beads of sweat on all our faces. He's too far into his story to notice.

"I was arrested - here, you see these marks?" Khalid presents his thin wrists to me and turns them over. Scars snake around them in white circles.

"My hands were tied with plastic ties. They were tied so tight. Other children were with me in the cell - they had the same ties. We would beg them to untie us, and they would only tie them tighter."

Khalid was held prisoner - in his old school.

"It is ironic, that they took me there to torture me, in the same place I used to go to school to learn. My father was actually the Principal there. They had taken over the school and made it into a torture centre. It wasn't a proper jail, I learnt later. It was a place they took you to first, before jail. To torture you. When I realised that was where we were going, I was so sad, I wanted to cry."

I pause the interview and ask gently if he wants to continue. He nods his head emphatically and continues before I can ask another question.

"I was terrified. There were 35 people taken in with me, and overall around 135 in the same room in the school as me. I remember one boy was only 12 years old. He was in prison for five days with me. His hands were bound behind him, just as mine were.

Khalid pauses and looks in my eyes. "What can he have done? He is a 12-year-old boy." I didn't have an answer. I don't know if anyone could answer that.

"After those first two days I was taken from the room to be interrogated. I had not eaten anything, had no water, and was extremely weak. I was hung up - from the ceiling with rope.

They hung me up by my wrists, by the plastic ties. My feet were above the floor. I was beaten."

Khalid continues and tells me that those who held him prisoner also took turns to stub out their cigarettes on him. He shows me the scars covering his arm and chest. We talk for ages after, about his hopes for the future, what he wants to do next. He makes some jokes about football, and we all laugh. But leaving that tent, I can't forget the image of this smart and funny 15-year-old boy begging to have his wrists untied.