‘Some years ago – let us say in the first half of the first decade of the twenty-first century – a young man arrives in the beautiful hilly country of Shangla in Pakistan. There he meets a very important person – a leader who, at that moment, is taking refuge in the mountains. In a year and a half’s time, this leader will move to a large white-walled complex in the town of Abbottabad.

‘After reaching the end of a rough track, the young man’s car can go no further. He is escorted on foot deep into the mountains until he arrives at what seems little more than a shepherd’s hut. It turns out to extend from a spacious cave. The leader he has come to meet is gentle, welcoming, softly spoken, unfailingly polite, wise, possessed of great learning, perhaps even divinity. He has been unwell but, in the mountain air, is recovering.’

Kareem stopped abruptly, tilting his head and listening. He checked his watch. Patrick glanced at Sara; she looked almost smug.

‘Time rushes,’ said Kareem, ‘but I will finish my story. This leader offers his visitor tea and sits him down on a rug beside him. He tells him that he is a special person among those fighting to banish the corruption of the west. And he has a special mission. The way he will explain this mission is through a parable.

‘“You are the fish swimming in the lake,” the leader begins. “Fishermen try to catch you but they do not know what size or age you are. You understand they would like to know you better, to possess you, to eat you. One day, you will see a bait dangling above and then striking the surface of the water you are swimming in. You will bite at it. When the bait is stuck inside your mouth and the fishermen are trying to pull you onto shore, you pretend to fight. You fight for a well-judged number of minutes and then you surrender. You relax. Your body ceases to thrash around. In your floppiness, you allow the fishermen to bring you onto shore, store you in their canvas bag and take you to their home. The fishermen are hungry and will soon want to cook and eat you. This you will not resist. When they have tasted and chewed you, they will swallow you and you will descend into their stomachs. You reach their entrails and you will stay inside there for as long as it takes to poison and rot them. However many years that might be. And when they die, your glory will live on for ever.”’

In the distance, emerging from the hum of the lights, Sara began to make out a low rhythmic sound. And now, as Kareem talked of ‘glory’, its origin was unmistakable. A helicopter approaching. Patrick and Sara exchanged a quick look and turned back to Kareem. His expression was fixed, unreadable.