‘As we ourselves were ensuring there were no safety issues at the barn, we intervened. It appears, I’m afraid, the one mistake was to return Kareem and his assistant—’

‘Aaqil.’

‘Yes… return them too quickly to their car. I’m not saying this is what happened, but Kareem and Aaqil would have had the know-how to plant a device in the car Patrick had hired. To be within close range as you turned into Reading services.’

Sara took her mobile phone out of her bag. She showed Isobel the text message sent from Patrick’s pay-as-you-go. ‘How did Kareem know my number?’

‘Have you changed it since you gave Marion your number in the restaurant?’

Sara sighed. ‘I suppose not. Phones yes, never the number.’

‘You have an answer.’ She looked up. The massive shape of an A380 was lumbering towards Heathrow. She waited for it to die down. ‘It’s easy for anyone who knows how, to find a phone number these days.’

‘Why would Kareem want to kill Patrick?’ asked Sara.

‘Sara, we do have to wait for the police investigation,’ replied Isobel gently. ‘It could have been suicide.’

‘He was killed. I know, you know. Even if it will never be proved.’ Sara thought she saw Isobel unsettled. She moved closer. ‘What are you thinking?’ she said. ‘Tell me – whatever it is.’

‘If you must, Sara. If Kareem had detected you were becoming too close to Patrick, that inner rage might have boiled over.’

Sara felt an acute awareness of that part of herself destroyed along with Patrick. ‘Am I safe from him?’

‘Of course. He’s being deported. Though I never felt he would physically harm you.’

‘He already had.’

‘If Kareem ever felt regret, that would be the only one.’

Sara allowed the idea to hang; she might once have believed he could feel sorrow or regret, but not now. ‘Have you listened yet to the conversation in the barn?’ she asked.

‘Yes,’ replied Isobel. ‘At the time.’

Sara shook her head, understanding ever more the layers of deceit. ‘So you heard his “parable” of the fish.’

‘Yes. It was entirely in character. There is no evidence whatsoever for anything other than the first “narrative”. When you related your own far-fetched fantasy – forgive me those words but they are accurate – of Kareem being some kind of long-term jihadist triple agent, I’m afraid he simply couldn’t resist. It was too good an opportunity for one of his mind games – to agitate and scare you. We will, of course, go over all his contacts, decisions, actions, everything, however much we already know the answers. I can’t guarantee that, even from outside the UK, he won’t continue playing games with you. But his only weapon is his phone. He poses no threat to you or our nation.’