Ashour witnessed horrific acts of torture and brutality when he was imprisoned.
We need you to help The Forgotten Millions. The Herald and World Vision are running a major campaign to raise funds and help the millions of children left homeless by war in Syria. With your help we can make a difference to the children and their families in desperate need throughout this region
One day, he was a prosperous dental surgeon. The next, he was taken from his car at gunpoint and thrown in a bloodstained cell, where he watched as the other prisoners were taken out, one by one, to be shot. Ashour tells Rachel Smalley how he survived.
"Do you want the whole story?" he asks.
"Yes, if you can," I say. "I hear it's quite a story."
His name is Ashour (surname withheld for his protection) and he will soon turn 30. He is an oral and maxillofacial surgeon from Mosul but for the past six months he has lived in a crowded church in Kurdistan, Iraq. He has a bag of clothes, some blankets and a pillow, but little else.
"It's not so bad," Ashour says. "I am displaced but I still have my life."
Ashour is one of two million Iraqis displaced after fleeing Isis and its jihadist agenda of torture, indiscriminate killing and religious persecution.
Almost one million have sought refuge in Kurdistan, the small, semi-autonomous region in the north of the country, sheltering in schools, informal tent settlements, churches, and the bare, concrete skeletons of unfinished buildings that pepper the Middle East's landscape.
I meet Ashour in Duhok, a city encircled by mountains in the rich, fertile basin of the Tigris River.
Isis fighters are 35km away at the border and engaging daily with the Kurdish Peshmerga, but the region is largely stable and remains under Kurdish control.
"Sometimes, the terrorists gain ground, sometimes they are pushed back," Ashour says.
He has found a temporary home in the Ancient Assyrian Church of the East. Bags of clothing, purple sofas, blankets and foam mattresses are stacked waist-high and serve as makeshift walls, neatly dividing the area into rooms for the 50 families now living here.
I speak to a mother with a newborn baby. She urges me to talk to the dentist. "Everyone here has a story," she says "but you should talk to the dentist. God is watching over that man."
Ashour shakes my hand. He is slightly built with bright eyes and a warm smile.
I tell him my name and ask if he speaks English.
"Of course," he says. "I am fluent."
Ashour places three plastic chairs outside the entrance of the church, and we sit down in the warm winter sun. His mother joins us. She doesn't speak English, but her eyes are trained on her son's face as he begins to tell his story.
"I am a dentist and an oral surgeon," he says. "I do reconstruction work. People who've had mouth cancer, or a car accident, or been hit by an explosion ... that sort of thing, but I specialise in impacted teeth."
He tells me he owns a house in Mosul and two homes northeast of the city in the Christian town of Tel Keppe. He has a private dental clinic too, and he shows me a photo on his phone of the waiting room and the operating theatre.
I tell him I like the modern, lime-green decor and he smiles.
"The operating theatre is very good. It had very good equipment. State of the art," he says.
The last time he saw his clinic was on August 3. The next day he was stopped by Isis at a checkpoint and arrested.
"I was travelling into Mosul to collect my pay cheque because I teach dentistry part-time at the university. I was owed six weeks' wages."
There were four Isis checkpoints on the road between Ashour's house and the university. He showed his Christian Iraqi ID card and was waved through the first three, but at the fourth he was stopped.
Mosul had been under Isis control for two months. The militants had rapidly advanced across the north and east of the country, and on June 10 Isis fighters swept into Mosul and took control of Iraq's second largest city in the space of a day.
Soldiers from the Iraqi army who were stationed in Mosul had panicked. Ill-equipped to deal with the size and strength of Isis, they abandoned their posts and fled to Baghdad and Kurdistan. The people of Mosul were left to fend for themselves.
"Isis was very different back then," says Ashour.
"The men in charge were soldiers from Saddam Hussein's old regime. They hated Shia and they hated Yazidis but they were tolerant of Christians."
By August, new leaders were beginning to emerge in the Isis hierarchy. They were less tolerant of Iraq's religious minorities and Isis checkpoints had become a lottery for every Iraqi, including Christians.
Ashour was told to get out of his car. "I thought it was a mistake, so I wasn't scared."
He waited at the side of the road for two hours until a convoy of Isis fighters arrived in a cloud of dust, driving late-model pick-up trucks.
The barrels of their AK-47s rested on their wound-down windows, and they wore dark glasses and keffiyehs loosely draped around their necks.
They signalled for Ashour to climb in the back. "I was the only Christian. The others were Sunni. Most of them worked for the Government."
He was driven 30km south of Mosul to a jail controlled by Isis, in al-Qyara. He was taken inside and guards took his wallet and phone, and then led him down a long corridor to a stifling hot, filthy cell. There were nine men jammed inside. Ashour became the 10th.
"The mattresses were stained with blood. There was old blood. New blood. It was everywhere."
One of the men in the cell was injured and bleeding.
"I saw him only that once. They came to get him in the afternoon and told us they were going to kill him. They took him outside and I heard the sound of gunfire. It was semi-automatic. An AK-47, I think."
In the days that followed, Ashour witnessed horrific acts of torture and brutality. Guards came to the cells and routinely beat and whipped the men, striking their bare flesh with wire and hosepipes.
"They beat the men who had worked for the Government. They were all killed. One by one. I saw it with my own eyes. The guards were trying to get information from them. They had bad wounds. They were bleeding. Then they were taken outside and shot and put in a big, deep hole."
I ask him how he knows about the "hole".
"They told us. Isis would come into the cell and say 'this man is going in the hole' and they would laugh. And then we would hear the shots."
"They will kill anyone who works for the Government or the army. It doesn't matter if you are Sunni, they will kill you too."
Ashour was told he would remain in jail until the guards were satisfied he didn't work for the Government. They checked his phone's text and call history too.
"They kept saying they were sorry. They kept saying they were sure I was a dentist."
On the second day, a senior Isis leader came to his cell.
"He told me they had been ordered to take everyone's property and spoils, but Christians should not be killed. And then he told the guards to get me fresh food. I ate cucumber, tomato and lamb. It was delicious."
The summer heat in the Middle East is unbearable at the best of times but in August it is at its fiercest. Ashour says the temperature in his cell reached more than 45C in the afternoon and the stench was overpowering.
"Blood. Faeces. Sweat. It was horrific."
He kept sane by telling himself he would be released, but he worried about his family. He knew his mother would fear the worst so he asked a guard if he could borrow his phone.
"I tried to call my mother so many times ... nine times, I think ... but I couldn't remember her number. I was furious. I wanted to get a message to her that I was alive."
He spent that night trying to remember the number and the next morning, he asked for the phone again. He tried another three times, but each time it was wrong.
"That's when I got angry. I told them I couldn't live this way anymore. I did not work for the Government. I did not work for the army. I was a dentist.
"I told them they had two options. They could kill me, or release me."
The guards spoke to the leader and he agreed that Ashour could go. They said they would drive him back through the checkpoints to his friend's house in Mosul, but first they offered him a shower.
"I laugh. I tell him if Isis said I was free to go, I would probably skip the shower.
"But I was covered in dried blood from the mattresses. I had a rash on my neck. I was filthy. It was so hot in that cell. So I had a shower. A fast shower."
They drove Ashour to Mosul and he stayed at his friend's house for five days.
Once there, he charged his phone and called his mother.
"She can't read so she didn't recognise my number. She answered the phone and said 'Hello? Hello?'"
I said "Mum. It's me. It's Ashour. She didn't say anything but she made a sound that I will never forget. It is a sound we make in the Middle East when we are happy. It is a scream and a cry all at once.
"She was crying. She kept saying 'It's my son. It's my son. He's alive'."
His parents, fearing Ashour was dead, had fled to Kurdistan. They told Ashour he must try to reach them, even though the roads had become dangerous. They said Christians were no longer safe to travel.
"Saddam's men were losing control, and the checkpoints were run by thugs. Savages. They were killing everyone."
Still, Ashour thought he would try his luck.
He asked a taxi to take him to the Kurdistan border but the driver refused. He said they would both be killed. Instead, he took Ashour to his home in Tel Keppe.
"I had no electricity, no food. There was no market. I was alone in my home. The neighbours had all gone."
On the 10th day, and when he feared he would never reach Kurdistan, the mosques began to broadcast a message.
"They said everyone should leave immediately or they would be killed. It was confusing. I didn't know what to do."
Unbeknown to Ashour, the siege of Sinjar was under way to the west of Tel Keppe. Isis fighters had trapped tens of thousands of Yazidi on Mt Sinjar, a religious minority living in the northwest of Iraq.
The United States had ordered airstrikes and the mosques were worried Tel Keppe might be bombed, or the village overrun by Isis fighters fleeing the bombing.
Ashour found a taxi driver who was willing to take a chance on the road. They drove back through Mosul and on to Kurdistan, negotiating 15 Isis checkpoints along the route.
"They weren't interested in Christians by then. They were trying to catch Yazidis from Sinjar and stop them reaching Kurdistan."
He reached the border, was waived through by the Kurdish Peshmerga and has now been living with his parents in the church in Dohuk for six months.