‘He didn’t betray Gus and me.’

Kate stood up. ‘I’ll meet you in Reception in twenty minutes. We’re a long way past the check-out time I agreed, so don’t be late.’

‘Why won’t you accept his apology?’ Fiona asked. She looked as if she was about to smash something or burst into tears, or both.

‘Let’s talk about this calmly when we get home.’

‘That’s just an excuse not to talk about it at all.’

‘I’ll see you in Reception in twenty minutes.’

Kate went to her own room and sat on her bed. She noticed that her hands were shaking, got to her feet and went into the bathroom. She stared at herself in the mirror. Her face was white, her eyes bloodshot. She looked exhausted, which was no surprise. The acute stomach and back pain that had been plaguing her had returned with a vengeance. It was as if someone had wrapped a belt around her chest and was slowly tightening it.

She felt physically terrible. She walked to her bed, lay down and tried to concentrate on the breathing exercises the psychologist she had been seeing had recommended. They seemed to make no bloody difference at all.

She forced herself upright, packed the last of her belongings and walked down the grand staircase to Reception.

They caught the four o’clock flight home, the entire journey conducted in more or less total silence. Julie had made a concerted effort to jolly the children along before they boarded the plane until she received a text at Passport Control. After that she’d retreated rapidly into herself. Kate made no headway in winkling out of her what the trouble was.

She left Fiona in theoretical charge of her brother at home in Battersea and reached MI6’s Vauxhall Cross headquarters just after eight. She stopped off at the ops room on the second floor, where she found Julie sitting next to Danny in front of a bank of computer screens. ‘I think we’ve found it,’ Julie said.

‘Grab a seat,’ Danny instructed. He had long dark hair, piercing blue eyes and pretty much always wore a black T-shirt, blue jeans and threadbare sneakers. He had a Chinese dragon tattooed around the side and back of his neck and the kind of easy smile that could stop grown women in their tracks. Or perhaps it was just Kate. She suspected he and Julie had once been an item but, if so, it was a rare outbreak of common sense on her friend’s behalf: her taste in men was usually abysmal.

Kate did as she had been told. The floor was covered with styrofoam coffee cups and takeaway food cartons that had yet to make it to the bin in the corner. In his eating habits, and the curious absence of any visible impact on his waistline, Danny provided another painful reminder of her former deputy, Rav, who’d had a similar penchant for chaining himself to his desk in a tunnel of intense concentration. It was what made Danny – and had made Rav – so good at his job.