Fouad, he noticed, was nowhere to be seen. Baba, on the other hand, had peeled away as soon as the police appeared, but only managed to walk a few feet before he was surrounded. He was now lying on the floor with three assault weapons pointing at his head. The Syrians were still standing, their hands raised, although the two men who had been waiting for them were gone. The Syrians had their backs to Marković, but one of them – Marković thought it might be Saad – was shouting at the police in Arabic. Around them, passengers huddled low or lay flat on the ground, giving the officers clear fields of fire if required. Saad’s right hand dropped, and he reached inside his jacket. At least three RAID officers opened fire simultaneously, two with pistols and one with a Heckler & Koch G36. They drew no distinction between Saad and Mahdi. Within seconds, both men were dead.

Louis was at the main station entrance when he heard swearing in his Bluetooth earpiece, before Harris’s voice gave the order to abort the operation. Louis listened for a while longer, until a woman’s voice announced that they’d lost Marković. Almost immediately, his own cell phone buzzed, and he answered.

‘We have him,’ said the voice on the other end. ‘He’s on Place Henri-Frenay, heading north.’

Louis took out the Bluetooth earpiece and replaced it with a wired earpiece and microphone connected to his own phone. He removed the SIM card and battery from the Android device that had been delivered earlier that morning, and debated breaking the SIM card in two. Instead he put it in his pocket, but dumped the phone and battery in a trash can. He wouldn’t have put it past Harris to embed a tracker in the phone, one that operated independently of the battery.

Louis walked away as more police vehicles pulled up outside the station, along with a pair of ambulances. His taxi was waiting on the street; the driver had come highly recommended, as selectively blind and deaf as the evolution of his breed would allow. As Louis got in, the voice in his ear told him that Marković had been making for the Reuilly-Diderot Métro station, but now looked as though he might be reconsidering. Moments later, Marković had hailed a cab, and his trackers were now following, all the time keeping up a constant flow of information from their cell phones to Louis’s earpiece.

‘North at present,’ Louis heard. ‘Do you think he’s going back to his hotel?’

‘Only if he’s dumb,’ said Louis, ‘and Marković doesn’t strike me as that.’

Louis was frustrated. Harris’s operation had gone south fast, but at least Marković wasn’t in the wind, not yet.