Rob could sense Isobel’s excitement, but he couldn’t share it. Staring glumly at the cloudy London sky he said, ‘OK. I get it. You could be right. The Black Book is therefore in Kurdistan. Somewhere. Not Britain, not Ireland. It was returned by Layard after all. The gang are wrong. Sure.’

‘Of course, darling,’ Isobel said. ‘But it’s not just in Kurdistan, it’s in Urfa. You see? The book says Urfa. Lalesh is of course the sacred capital of the Yezidi. But the ancient administrative capital, the political capital, is Urfa. The Book is in Sanliurfa! Hidden away somewhere. So Layard took it there, to the Yezidi. And in return the Yezidi told him where to find the great antiquities, the obelisk of Nineveh, and so on. And Canning and Layard got the fame they wanted. It all fits!’

Rob’s mouth was dry. He felt a surge of sarcastic despair. ‘OK. That’s great, Izzy. It’s possible. But how the hell do we get hold of it? How? The Yezidi just tried to kill us. Sanliurfa is a place where we are not wanted. You suggest we just march back in and demand they hand over their sacred text? Anything else we should do while we’re at it? Walk across Lake Van perhaps?’

‘I’m not talking about you,’ Isobel sighed, firmly. ’I mean me. This gives me a chance! I have friends in Urfa. And if I can get to the Black Book first-even just borrow it for a few hours, just make a copy-then we have something on Cloncurry. We can exchange our knowledge for Lizzie and Christine. And I really do know Yezidi people. I believe I can find it. Find the Book.’

‘Isobel-’

‘You can’t dissuade me! I’m going to Sanliurfa, Rob. I’m going to find the Book for you. Christine is my friend. And your daughter feels like my daughter. I want to help. I can do it. Trust me.’

‘But, Isobel, it’s dangerous. It’s a wild theory. And the Yezidi I met certainly thought the Book was still in Britain. What’s that about? And then there’s Kiribali-’

The older woman chuckled. ‘Kiribali doesn’t know me. And anyway I’m sixty-eight. If I get beheaded by some psychotic Nestorians so be it, I won’t have to worry about a new prescription for my spectacles. But I think I’ll be all right, Rob. I already have an idea where the Book might be. And I’m flying to Urfa tonight.’

Rob demurred. The hope Isobel offered was faint, very faint, yet it also appealed to him-perhaps because he had no other real hopes. And he also knew Isobel was risking her life, whatever the outcome. ‘Thank you, Isobel. Thank you. Whatever happens. Thank you for this.’

‘De nada. We’re going to save those girls, Rob. I will see you soon. All three of you!’

Rob sat back and rubbed his eyes. Then he went out for the afternoon, and drank alone in a pub. Then he came back, for a few minutes, and couldn’t bear the silence so he returned to the streets and carried on drinking. He went from pub to pub, drinking slowly and alone, staring at his mobile every five minutes. He did the same the next day. And the next. Sally rang five times. His friends from The Times rang. Steve rang. Sally rang. The police didn’t ring.

And through it all Isobel called, almost every other hour, giving him her progress in Urfa. She said she felt she was ‘close to the truth, close to the Book’. She said some of the Yezidi denied they had the Book, yet some thought she was right, that the Book had been returned, but they didn’t know where it was kept. ‘I’m close, Rob,’ she said. ’I’m very close.’

Rob could hear the sound of the muezzin in the background of this last call, behind Isobel’s earnestly encouraging voice. It was a strangely horrible feeling, hearing the hubbub of Sanliurfa. If he’d never gone there in the first place none of this would have happened. He never wanted to think about Kurdistan ever again.

For two more days Rob did nothing but agonize. Isobel stopped calling. Steve stopped calling so much. The silence was unendurable. He tried to drink tea and he tried to reassure Sally and he went to the supermarket to buy some vodka; then he got back home and went straight to his laptop, yet again. He was doing it by rote, now: expecting nothing.

But this time there was the little symbol of an envelope on his screen. A new email had arrived, and the new email was from…Cloncurry.

Rob opened up the message, his teeth gritted with tension.

The email was empty: apart from a link to a video. Rob clicked the videolink: the screen fizzed and cleared, and then Rob saw Christine and his daughter in a bare room, again tied to chairs. The room was a little different, smaller than the last one. The prisoners’ clothes had changed. Obviously Christine and Lizzie had been moved.

But it wasn’t any of this that caused Rob to shiver, with a harsh new fear, and a deeper anguish: it was the fact the two hostages were hooded. Someone had put thick black hoods over the heads of the girls.

Rob grimaced. He remembered his own terror in that foul black hood in Lalesh. Staring at the darkness.

These new, chilling scenes on the video-of Lizzie and Christine, silent, hooded, and lashed to the chairs-lasted a long three minutes. After then Cloncurry appeared, talking directly to the webcam.

Rob stared at the lean and handsome face.

‘Hello, Rob! As you can see we’ve moved to more exciting accommodation. The girls have got hoods on because we want to frighten the living fuck out of them. So. Do tell me about the Black Book. Are you really on to it? I need to know. I need to be kept fully informed. Please don’t keep secrets. I don’t like secrets. Family secrets are such terrible things, don’t you think? So tell me. If you still want a family, if you don’t want your family dead, tell me. Tell me soon. Don’t make me do what I don’t want to do.’

Cloncurry turned away. He seemed to be talking to someone behind the webcam. Murmuring. Rob could hear laughter from somewhere off-cam. Then Cloncurry faced the camera again. ‘I mean, let’s get down to basics, Rob. You know what I like to do, you know my metier. It’s sacrifice, isn’t it? Human sacrifice. But the trouble is I am spoiled for choice. I mean: how shall I kill your daughter? And Christine? Because there are so many methods of sacrifice, aren’t there? What are your favourites, Rob? I rather like the Viking ones. Don’t you? The blood eagling, for example. The professor was quite alarmed I believe, when we took out his lungs. Alarmed and somewhat impressed, if I say so myself. But we could have been so much…crueller.’ Cloncurry smiled.

Rob sat in his flat, sweating.

Cloncurry edged nearer the camera. ‘For instance, there is a delightful rite the Celts had. They would impale their victims. Especially young women. First they would strip them naked, then they would carry them to a field, lift them up on top of a sharp wooden stake, and pull their legs apart, and then-well then just kind of yank them down, onto the stick. Impaling them. Through the vagina. Or the anus maybe.’ Cloncurry yawned, then continued, ’I really don’t want to do that to your lovely girlfriend, Rob. I mean, if I did shove a pike up her snatch she would just bleed all over the rug. And then we’ll have to buy a big carpet cleaner. A needless expense!’ He smiled again. ‘So just give me the fucking Black Book. The Tom Whaley shit. Stuff you found in Lalesh. Give it over. Now.’

The webcam wobbled slightly. Cloncurry reached out and steadied it. Then he said, direct to camera, ‘And as for child sacrifice, with little Lizzie over here. Well now…’

He got up and walked over to Lizzie’s chair. With a magician’s flourish, Cloncurry whipped off the hood-and there was Lizzie. Staring, terrified, at the camera, the leather gag tight around her mouth.

Cloncurry stroked the girl’s hair. ‘So many methods, just the one little girl. Which one shall we choose? The Incans would take children up mountains and just kill them by exposure. But that’s rather slow, I feel. Rather…boring. But how about one of the more refined Aztec methods? You may, for instance, have heard of the god Tlaloc?’