The horrible image of the baby’s face filled Rob’s thoughts. The terrible, silent scream on the baby’s face. He shuddered. Who the hell would bury a child alive? In a jar? Why? What was the evolutionary purpose? What could drive you to do that? What kind of God demanded that? What had happened at Gobekli? Another thought occurred to him as the car turned onto a thrumming seafront. ‘Wasn’t Abraham linked with the Canaanites?’

‘Yes,’ said Christine. ‘When he left Haran and Sanliurfa he descended into the land of the Canaanites. That’s what the Bible says anyhow. Hey, I think we’re here.’

They were just outside a ferry terminal. The concourse was heaving: with children, and girls on bicycles, and men carrying boxes of sesame biscuits. Again Rob sensed the fault line of civilization running right through the city: it was almost schizophrenic. Men in jeans stood by men with lavish Muslim beards; girls in mini-dresses laughed on their mobile phones next to silent girls in black chadors.

They bought tickets and headed for the top deck. Strolling by the taffrail, Rob felt his spirits lift. Water, sunlight, fresh air, cool breezes. How he had missed this. Sanliurfa was so ferociously landlocked, sweltering in the bowl of Kurdistan.

The boat chugged along. Christine pointed out some of the sights of the Istanbul skyline. The Golden Horn. The Blue Mosque. Topkapi Palace. A bar where she and Isobel once got very drunk on raki. Then she reminisced about Cambridge, and her university days. Rob laughed at her stories. Christine had been quite wild. Before he knew it, the ferry-horn blew: they’d reached the island.

The little pier was crowded with Turks, but Christine spotted Isobel immediately. It wasn’t hard. The silvery-haired old woman was conspicuous amidst the darker faces. She was wearing swirling clothes. An orange silk scarf. And lorgnettes.

They walked down the gangplank. The two women hugged and then Christine introduced Rob. Isobel smiled, very graciously, and advised Rob that her house was a half-hour walk.

‘I’m afraid we don’t have cars on the islands, you see. They’re not allowed. Thank God.’

As they threaded their way, Christine told Isobel the whole extraordinary story of the last few weeks. The horrible murder. The incredible finds. Isobel nodded. She sympathized over Franz. Rob detected an almost mother/daughter relationship between the two women. It was touching.

Considering this, he was reminded of Lizzie again. Lizzie would like this island, he decided. It was pretty, yet faintly mysterious too, with its wooden houses and tamarisk trees, its crumbling, Byzantine churches and cats sleeping in the sun. All around them was glittering water, and in the distance was the famous skyline of Istanbul. It was gorgeous. Rob firmly resolved to bring her here, one fine day.

Isobel’s house was glamorously old: a cool summer retreat for Ottoman princelings. The white stone house stood by a well-shaded beach and looked across the water towards some of the other isles.

They sat down on cushioned sofas and Christine finished the narrative of Gobekli and the last few weeks. The whole house was quiet as she finished the tale with its outrageous coda: their near-kidnapping at the museum.

Silence sang in the air. Rob could hear the plash of water beyond the half-open shutters, and the creak of pine trees in the sun.

Isobel toyed languidly with her lorgnettes. They finished the tea. Christine shrugged at Rob as if to say, maybe Isobel can’t help. Maybe the puzzle is too difficult.

Rob sighed, feeling tired. But then Isobel sat up: alert, with her eyes sparkling. She asked Rob to show her the mobile phone photo of the symbol on the jar.

Rob fished in his pocket, retrieved the phone and flicked to the image. Isobel contemplated the photo. ‘Yes. As I thought. It’s a sanjak. A symbol used by the Cult of Angels.’

‘The cult of what?’

‘The Cult of Angels, the Yezidi…’ She smiled. ’I’d better explain. That remote part of Kurdistan around Sanliurfa is a remarkable breeding ground of beliefs. Christianity, Judaism and Islam all have strong roots there. But there are other, even older, faiths, that inhabit the Kurdish lands. Like Yarsenism, Alevism, and Yezidism. Together they are called the cult of angels. These religions are maybe five thousand years old, maybe older. They are unique to that part of the world.’ She paused. ‘And Yezidism is the oldest and strangest of all.’

‘In what way?’

‘The customs of the Yezidi are intensely peculiar. They honour sacred trees. Women must not cut their hair. They refuse to eat lettuce. They avoid wearing dark blue, because they say it is too holy. They are divided strictly into castes, who cannot marry each other. The upper castes are polygamous. Anyone of the faith who marries a non-Yezidi risks ostracism, or worse. So they never marry outside the faith. Ever.’

Christine interrupted. ‘Hasn’t the Cult of Angels basically died out, in Turkey?’

‘Almost. The last of the Angelicans live mainly in Iraq, about half a million of them. But there are still a few thousand Yezidi in Turkey. They are fiercely persecuted everywhere, of course. By Muslims, Christians, dictators…’

Rob asked, ‘But what do they believe?’

‘Yezidism is syncretistic: it combines elements of many faiths. Like Hindus, they believe in reincarnation. Like ancient Mithraists, they sacrifice bulls. They believe in baptism, like Christians. When they pray they face the sun, like Zoroastrians.’

‘Why do you think the symbol on the jar is a Yezidi symbol?’

‘I’ll show you.’ Isobel walked to the bookshelf on the far wall and returned with a volume. Halfway through the book the found a picture showing a curious copper stick with a bird poised on the top. The book said the symbol was a ‘Yezidi sanjak’. It was the exact same symbol inscribed on the jars.

Isobel shut the book and asked Christine, ‘Now. Tell me the full names of the workmen, at the site. And the surname of Beshet at the museum.’

Christine closed her eyes, trying to remember: faltering a little, she recited a list of half a dozen names. Then a few more.

Isobel nodded. ‘They are Yezidi. The workmen, at your site. They are Yezidi. And so is Beshet. And I presume the men who came to kidnap you were Yezidi too. They were protecting those jars in the museum.’

‘That makes sense,’ said Rob, quickly working it through in his mind. ‘When you look at the sequence of events. What I mean is: when Christine went to Beshet for the keycode, he gave it to her. But then he must have called his fellow Yezidis and told them what we were doing. And so they came to the museum. They were tipped off!’

Christine interrupted. ‘Sure. But why should the Yezidi be so worried about some old jars? However ghastly the contents? What’s it got to do with them now? Why the hell were they so desperate to stop us?’

‘That’s the nub.’ said Isobel.

The shutter had stopped creaking. The sun sparkled on the placid waters beyond the window.

‘There’s one more thing,’ said Isobel. ‘The Yezidi have a very strange god. He is represented as a peacock.’

‘They worship a bird?’

‘And they call him Melek Taus. The peacock angel. Another name for him is…Moloch. The demon god adored by the Canaanites. And another name for him is Satan. According to Christians and Muslims.’

Rob was nonplussed. ‘You mean the Yezidi are Satanists?’

Isobel nodded cheerfully. ‘Shaitan, the demon. The terrible god of the sacrifice.’ She smiled. ‘As we understand it, yes. The Yezidi worship the devil.’