IN SEPTEMBER 2014, a 22-year-old man named Yassin left his home in France to join ISIS. Three weeks later, he was in a makeshift hospital in Syria, having taken a bullet for the cause. His intestines were partially gone, his hip was broken and he didn’t even know if the man who’d operated on him was a real doctor.

But out of this misery and pain came a saviour, a brave soul who charged into the deadly territory, with no training or resources, to rescue him.

It was his mother.

The story of Yassin, and how his family ventured into the most dangerous region in the world to save him, is one of the tales in The Returned: They Left to Wage Jihad, Now They’re Back, by David Thomson.

Yassin, the Arab-Muslim son of French doctors, achieved high marks in high school and planned to study medicine like his parents.

But after failing several key college exams, he soothed his frustration watching Islamic State videos on social media, yearning for the life of wealth, leisure and accomplishment they falsely depicted.

“They show you videos of shining knights saving the world,” Yassin told Mr Thomson after his return to France. “There was a kind of madness to it, almost a collective trance, that convinces you to do it and that everything will be fine.”

Yassin travelled to Syria and found his way to ISIS. He was unprepared for the chaos.

Along with other new recruits, he was told they would be sent to Deir Ez-Zor Airport in northeast Syria, where ISIS and the Syrian regimen had been engaged in heavy fighting for over three years.

A few nights before they were sent — barely 10 days after Yassin arrived in Syria — they were given military “training.”

“Fighters came with trucks loaded with Kalashnikovs,” Mr Thomson writes. “Each recruit received an assault rifle and one full clip of bullets. Two days to learn to shoot while sitting, standing and lying down. And then they were sent to the front.”

Three days after they arrived, the Syrian regimen began a relentless bombing campaign accompanied by gun and rocket fire.

Yassin was shot in the lower back, the bullet ripping apart his intestines.

He was shipped to an ISIS hospital in Mayadin, Syria, in so much pain that he wished for death.

Back in France, his parents were desperate to know where their son went.

Yassin hadn’t told his family he was leaving, and they only learned of his whereabouts from a stranger.

“Just after Yassin’s departure,” Mr Thomson writes, “one of his sisters received a telephone call from a woman informing her that her brother was in Syria. The dialling code was from Great Britain.

Jihadists often use applications that allow them to generate false numbers.”

Yassin’s mother, Nadia, kept the numbers that called and frantically tried to reach her son.

“I would send messages. ‘Please, take pity on me, tell my son to contact me, please.’ I’d try to make them feel sympathy for me so that he’d contact me. And then, the next day, sometimes, he would send a message on WhatsApp.”

In the suffering over their missing son, the family’s life became “centred on the telephone.”

“We would even take turns going to the toilet,” Nadia told Mr Thomson, “to be sure that one of us could always pick up quickly. He called once when we were driving; we went into a tunnel and he called. Yes … Hello? Then we were cut off. He didn’t call back afterwards. It was horrible.”

Five months after his departure, Yassin contacted them via Skype, and his face appeared on the screen. He looked gaunt, having lost a tremendous amount of weight.

It was clear he wasn’t well.

He said he was staying in an ISIS convalescence home, and his parents barely recognised him.

“Yassin, usually a joking and lively young man, appeared in the dark, very weak, expressing himself painfully in a low voice. He tried to hide his wounds in the shadows,” writes Mr Thomson, who makes clear that the family assumed Yassin was not alone and could not speak freely.

“They talked for several minutes. Answering their barrage of questions, he tried to be reassuring but remained evasive. As doctors, his parents were in no way fooled.”

Nadia knew her son needed help and became obsessed with the idea of rescuing him.

“Our son needs us,” she thought. “I’ll feel guilty all my life if he needed me and I didn’t do anything. I have to go and see what’s wrong with him. If I stay here, I’ll lose my mind.”

After some internet research, Nadia decided the best chance they had to rescue Yassin was for her and her husband, Faisal — who supported his wife’s plan — to volunteer as doctors for ISIS.

But there was a complication. The couple had two teenage daughters, age 14 and 15. When new recruits join ISIS, the group has them provide all their personal information including who’s in their family, so ISIS knew about the girls. If the couple showed up pledging fealty without their daughters, it would ring hollow and ISIS could execute them on the spot out of suspicion. The plan would only work if the girls came along, a tremendous risk given that women and girls there were often used as sex slaves.

But when they discussed it as a family, the girls were adamant.

“We want to see him, too,” they said. “He’s our brother.”

Together, they decided that the entire family would travel to Syria and pretend to join ISIS in order to rescue Yassin.

“They prepared in secret,” Thomson writes. “To friends, family and colleagues, they pretended they were leaving for a few months to the West Indies, to work as medical replacements.

“We didn’t know how long we’d be gone,” said Nadia. “To make it believable, everyone had to think we were really going to work there.”

When they were ready, they contacted Yassin via WhatsApp and told him to recommend them to his emir. Then, they booked a flight to Turkey.

Upon arrival, they were met by an ISIS official, taken to a hotel and given fake Syrian IDs.

Once inside ISIS territory, Faisal was taken to see Yassin and found him in grave condition, having lost almost one-third of his body weight.

Recognising the need for better care, Faisal arranged for Yassin to be transferred to a hospital in Raqqa in exchange for him and Nadia agreeing to work there as doctors. They were also provided with an apartment.

While working at the hospital, Nadia insisted that her daughters never leave her side. They nursed Yassin back to health within a few months and then had to figure out the hard part — how to get out.

Since ISIS had forbidden outside travel, requesting a pass was a great way to get yourself suspected of espionage and sentenced to death.

Regardless, the couple requested a travel pass to pick up a fictional third daughter, who they said was pregnant and wished to join her family so she could join the caliphate. This request was granted.

The family contacted their lawyer in France, who arranged for an official at the Turkish consulate to meet them at the border. The next morning, the family piled into a Kia that ISIS had loaned them and embarked on their journey home.

When Faisal presented his pass at the first ISIS checkpoint, he was informed that since it was Saturday, the Turkish border was closed. By this point, they couldn’t return, as their packed car would have raised suspicion.

Faisal told the guard they had arranged for a smuggler to bring their daughter across the border that day. When the guard replied, “ ‘It’s not possible. Give me the smuggler’s number,’ ” Faisal pretended not to have a telephone.

They were ordered to pull the car to the side of the road and waited an agonising hour as the guards deliberated, then stopped all work for one of their daily prayers. But when Faisal realised the guard hadn’t looked back at them in some time, he slowly drove away.

Obstacle number two came just 10 meters before the Turkish border, at a second ISIS checkpoint.

Seeing the approaching car, two men ran at the family, armed with Kalashnikovs. When Faisal showed his pass, one of the men asked who had allowed them through. He told them about the first guard, and the man said he would call the post to verify his claim. And then the family got ridiculously lucky.

“At that very moment,” Mr Thomson writes, “a Syrian refugee tried to climb the border wall but fell and hurt himself.”

When the guard saw the refugee, he hung up the phone, told Faisal to wait there and ran to the man. “If he had contacted the first roadblock,” Faisal later said, “we were dead. We would have been imprisoned.”

Instead, Faisal turned the car around and drove back toward ISIS territory.

They drove around for a while and then called the official at the French consulate, who said he’d arrange for the Turkish authorities to contact the ISIS checkpoint, letting them know the family could pass through.

“No, anything but that!” Faisal told the man. “You’d be signing our death warrant!”

Out of options, Nadia saw just one solution.

“Drive down along the wall, along the border,” she said. “There’s got to be a way through.”

And so they drove, with no idea of their ultimate destination.

“Along the way,” Mr Thomson writes, “an old Syrian shepherd told them about an abandoned border gate that had been closed for a long time, used by illegal immigrants.”

They found the gate late that afternoon. They called their contact again. He met them there accompanied by members of the Turkish military, and they crossed into safety.

Yassin had spent seven months in Syria; his family, three.

Upon his return to France, he was “placed in pre-trial detention in [a] prison hospital in Fresnes,” Mr Thomson writes. “Wearing an electronic ankle bracelet, and with his identity papers confiscated, Yassin is now trying to resume a normal life, navigating between family and judicial obligations, in particular going to see a psychiatrist to combat [his] radicalisation.”

At the time of the book’s writing, Yassin was back in school and awaiting trial on charges of “criminal association, for the purpose of preparing acts of terrorism.” If convicted, he faces 10 years in prison.

As for the family, “they too were suspected by the police of having ties to [ISIS],” Mr Thomson writes. “Why did they leave for Syria without informing the authorities? Why did they stay almost three months, agreeing to work for the Islamic State? Why did they put their two daughters at risk, exposing them to the possibility of being indoctrinated, married to a jihadist or even killed in a bombing raid?

“To all these questions, Nadia and Faisal respond with the same answer: Their goal was to save Yassin. In the end, no charges were filed against them.”

Nadia and Faisal are now adjusting to their new reality as the family of a suspected terrorist and figuring out how to move on from there.

“We’re just trying to make the most of life now,” Nadia said. “Your life can change overnight, so quickly and so cruelly, that you have to know how to make the most of it. The past has become so dark and painful that we don’t want to think about it anymore. It’s time to look to the future now.”