‘Nor can you expect either of us to comment on any part of ongoing investigations made within the remit of this Inquiry.’

‘You make an inference about “remit” with which I might not necessarily agree,’ said Dame Isobel, ‘but that’s not relevant to me being here.’ Sara was beginning to see how this precise, careful, evenly modulated woman had unobtrusively risen to the top. ‘To cut to the chase, there’s something you need to know about Kareem.’

‘About his activities?’ asked Patrick.

‘Allow me, Patrick. As you’re aware, Kareem joined the staff of the Security Service in late 2005 under conditions which had to be kept secret. Over the coming decade, he performed services for the British nation for which its people would honour him if they were ever able to know. As the Islamist threat adapted, so too did Kareem. In the summer of 2016, in the role he was playing as an important figure in British Islamist circles, he travelled to Mosul in Iraq for a meeting with leaders of ISIL, DAESH, IS, whatever you like to call it. During that meeting he buttressed his trusted position with those leaders. He was also able to impart to us information of enormous potential future interest about their activities and habitats.’

She paused, turning to the tray of coffee and biscuits. ‘Could I have a cup, please, as someone has so considerately prepared it? I rarely talk as much as this.’

‘Of course,’ said Patrick. Sara suspected there was nothing genuine about the request. This was someone who understood how to play an audience; an unexpected talent belied by her appearance. Isobel poured a splash of milk into her cup and reached into her bag for a pack of sweeteners. She ejected one, dropped it in, slowly stirred, took a sip and resumed her story.