‘No, silly boy! Jimmy’s booked me a flight to Málaga tomorrow. He says we should stay there where it’s safe.’

‘In Spain?’

She shrugged, as if it was what any sensible person would do. ‘He has a sea-view flat.’

‘Oh, fine, then.’

He could feel the familiar simmering irritation. She had dragged him back from Oxford to book her a minicab.

Suddenly her face crumpled.

‘What is it, Mum?’

She turned her eyes up to him, wide, full of love and longing. ‘It’s Karza.’

‘Right.’ His heart sank.

‘They still don’t know where he is. Jimmy’s been onto the Foreigners’ Office again—’

‘Foreign Office, Mum.’

‘Yes, that’s right, and they wash their hands of him.’

She didn’t need to say any more. A year ago, his brother and two of his equally useless and misguided mates had boarded a flight to Istanbul, made their way to the border, crossed over to Syria and enlisted with the rebels. Knowing Karza, Sam expected he’d be back in three weeks. But after a month they’d got a photo of him holding an AK47, a pair of bandoliers crossed over his shoulders. And for the first time in as long as Sam could remember, Karza was grinning. He had found his calling.

‘Have you asked Bala?’

She threw up her hands and clasped her forehead. He had heard that Bala, one of Karza’s fellow fuckwits, had come back four months earlier with a serious leg wound. ‘He stays in his room twenty-four out of seven. Says nothing to his mama, not even please and thank you for his foods. So I go there myself. I ask, I beg, “Where is Karza?” He tells me to – I can’t say the dreadful words. Sammy, please, can’t you do something?’ His mother tilted her head to one side and looked him up and down, as if his drenched linen suit was a uniform that conferred on him some official status.

‘Now you are a doctorate, can’t you at least do that one thing?’

From as early as he could remember he and his brother had gone separate ways. While Karza had stuck resolutely with the other Muslim kids, Sam had made a point of courting English friends, copying their habits and manners, like a method actor studying for a role he intended to play for the rest of his life. He had adored Britain from the moment they arrived. He couldn’t believe his luck to have been exiled from what he saw as a backward place, a cauldron of prejudice and religious dogma. He loved school, and his teachers loved him: he gobbled up knowledge as if it was ice cream. He had had no time for Karza and his friends, who seemed bent on denying themselves any hope of advancement.

And yet their mother doted on his brother.