In early August, in an attempt to get back into the routines of daily life, Daniel took the train out to Hillerød to visit his old college, where he had learned photography. They had offered him a room and the opportunity to teach a photography course. He needed to be somewhere where it was once more only about photography.

While he sat on the train he read a news item: President Barack Obama had announced that the Americans were going to bomb IS in Iraq. After the capture of Mosul and the declaration of a united caliphate across the Iraq−Syria border, IS had moved forwards in a significant offensive in several places in Iraq and for a moment had even threatened Baghdad.

Daniel looked around. There was a mother with a crying child and a young couple who were holding hands. For them it was just a matter-of-fact news update, as it would have been for him no more than a year and a half earlier. But he knew that the president’s announcement about bombing Iraq could cost the lives of people he knew.

While he sat there on the train, somewhere between Copenhagen and Hillerød, he lost all hope for James and the other remaining hostages. Obama’s political decision was a death sentence. He grabbed his mobile and called Pierre.

‘Have you heard?’ he asked.

‘Yes,’ replied Pierre.

They didn’t need to say anything else.

· * ·

The United States was drawn back to the war zone in Iraq less than three years after its forces had left the country at the end of 2011, following a lengthy campaign that began in 2003. The first bombings by American aircraft took place on 8 August 2014. Obama had prided himself on having ended the two wars in Iraq and Afghanistan, but now the Americans were back at the invitation of the Iraqi government and a failed army that needed help. The Kurds’ otherwise effective defences in northern Iraq had also been overrun several times. Moreover, Mosul, which IS had captured, wasn’t far from the Kurdish capital of Erbil.

The American military presence could also be interpreted as a tidying-up campaign following the recent war. The United States had itself played a role in creating the leader of the organization that they were now bombing, when Baghdadi had been held in their prison at Camp Bucca. Beyond that, the long-standing US policy failure regarding the Ba’ath Party and the Iraqi army had added fuel to the flames, which were fanned by the Shia Party’s exclusionary policy towards the country’s Sunni Muslims.

There were now several former Saddam supporters at the head of the IS leadership. At the same time the Sunni insurgency and the Shia rulers had both effectively marginalized anyone outside their own sect in the struggle for power that had pushed Iraq over the edge.

The Americans wanted to eliminate IS in Iraq, to which the Islamists responded promptly. IS was going to take revenge on President Obama and his policies in the Middle East.

· * ·

Arthur walked around restlessly, thinking about the wording of the next message to be sent. After a long silence, James’s family had finally received an email from the kidnappers. It was 12 August, just four days after US planes began bombing IS in Iraq.

On the basis of the email, Arthur judged that it had to have come from the same people who had previously written to the Foley family and to Daniel’s parents. The email contained a message to the US government and the family that they would kill James as a consequence of the bombs raining down on Iraq. It didn’t sound like either an attempt at extortion or an aggressive proposal for negotiations. It just sounded like a statement of fact, thought Arthur. Yet the family had to try to persuade the kidnappers to change their minds.

IS had succeeded in illustrating the difference between the European approach to hostage negotiations and the usual position of the United States and the United Kingdom, which was also why Arthur couldn’t do anything. In Daniel’s case, he had had a free hand to act without government interference.

In James’s case, the US authorities had been trying to bulldoze the investigation and had wasted valuable time looking for James in Damascus; and when there had finally been an opportunity in December 2013, the family had nothing to negotiate with, because they weren’t allowed to pay – or collect money for – a ransom.

Arthur feared the worst, in which case James would be the first hostage he had ever lost in his career.

· * ·

While in the United States they were battling for James’s life, Daniel was settling into his seat on a plane to Paris. He was going to meet Pierre. They wanted to drive around England and Scotland together for a month. It was going to be just the two of them – along with the shared experience that only they could fully understand. Daniel was also looking forward to seeing Pierre in the surroundings he had talked so much about during his captivity, rather than as a hostage with a grey blindfold hanging around his neck, waiting for a cell door to be flung open.

At the airport Daniel came out into the arrival hall and immediately spotted Pierre, who was standing slightly back, behind the other people waiting. They gave each other a long hug.

He was the same as ever, in a thick black jacket, black jeans and leather shoes. His hair was shorter and he had shaved off his beard.

They drove to a house where some of Pierre’s anarchist friends lived and spent the night in the garage. The next day, they took the train to his parents’ house north-west of Paris, on the roaring river just outside the city of Rouen.

Pierre’s mother picked them up in a car with their dog Olaf, who always came for the ride. She drove them along narrow roads until they turned down a dirt track at the end of which stood Pierre’s childhood home. Olaf was jumping up around their legs as they made their way to Pierre’s father, who was waiting in the living room. Daniel could speak neither French nor Spanish, so Pierre translated during a dinner of delicious French food that his mother had prepared.

Pierre’s world was exactly as he had described it in prison. His father’s sculptures towered above Daniel’s head as he came into the workshop, where tools and gadgets were scattered between metal formations that looked like a mixture of animals and humans. There was an old boat and some rusty motorcycles that Pierre wanted to refurbish, and in the shed behind the house was Tonton the donkey.

‘I felt bad about leaving you all,’ Pierre told Daniel when the conversation turned to their captivity.

He still felt it was wrong to be bought out of the hands of the Islamists.

‘The worst thing is that I accepted it,’ said Pierre. ‘I wasn’t a human being any more, but an object that could be sold.’ After his return Pierre had agreed to illustrate a children’s book that he and their fellow former prisoner Nicolas Hénin were writing. It was about a daddy hedgehog who disappeared from his hedgehog family.

Pierre and Daniel spent a couple of days preparing for their trip. They furnished the silver car with mattresses and a nifty device that enabled them to fold down the seats and flip open a bed in the back.

Before they headed for the ferry to England, they first made a stop farther south at a French farm to attend Nicolas Hénin’s wedding. Daniel drove, because Pierre had no driver’s licence. When they finally reached the farm and the lawn where the wedding was to be held, they met a happy Nicolas dressed in jacket and tie.

‘Hi Daniel, welcome! How good it is to see you,’ he said, smiling, before quickly moving on to welcome the other guests, including correspondents and journalists from around the world.

Pierre and Daniel had been assigned a room in the farmhouse where they could spend the night, while other guests slept in tents. When the party and the music shut down at around 1 a.m. Daniel rushed up to the bartender, who was about to pack up, and asked him to leave them a few bottles of wine. He carried them up to the room, where he and Pierre sat on the floor and laughed, joked and drank. They consumed so much wine that Pierre got drunk for the first time in his life. When they woke the next morning, 17 August, with throbbing headaches, Daniel started laughing again.