‘Salubrious,’ he said, looking around.

‘It was the best safe house I could find at short notice,’ she said. She was wearing a blue blazer over a white and blue checked dress and her chestnut hair was an inch or so shorter than when he’d last seen her in Belfast. ‘MI5 does have a particularly nice office in the British Museum but I thought you’d be happier being closer to Paddington.’

Shepherd took off his coat and sat down on the sofa. Button picked up her briefcase, pulled over a wooden chair and sat down opposite him. She clicked the double locks of her case, opened it and took out an A4 manila envelope.

‘How much do you know about pirates?’ she said, opening the envelope.

‘Yo-ho-ho and a bottle of rum?’

‘Not so much Long John Silver, more Somalis in the Gulf of Aden.’

‘Holding ships for ransom and making a mint, from the sound of it.’ He frowned. ‘But East Africa is a bit out of MI5’s manor, isn’t it?’

‘Turns out it’s a bit closer to home,’ she said, pushing a couple of surveillance photographs across the table. One was a close-up of a short, stocky man in a hoodie, his head down as he spoke into a mobile phone; the other was of the same man but wearing a Chelsea shirt and climbing into the back of a large Mercedes. ‘This is Wiil Waal, or “Crazy Boy”. His real name, in as much as Somalis have real names, is Simeon Khalid.’ She put down a close-up of the man’s face. ‘He’s twenty-four but looks older.’

Button slid out another photograph and pointed at a mugshot of a black man in his forties, his face pockmarked with old acne scars, his nose squashed flat against his face. ‘This is his elder brother, Abshir. He was taken by security forces in northern Somalia in 2010 and is behind bars awaiting trial. He was one of the founders of the new wave of Somali pirates, a particularly nasty piece of work, and an Islamic fundamentalist. He’s worth in excess of twenty million dollars but the US have got most of it. The Treasury Department targeted him a while back and have been freezing his assets wherever they can find them. The family business was taken over by one of Crazy Boy’s uncles.’

She put two more photographs on the table, surveillance pictures of a group of half a dozen hard-faced men in a skiff, AK-47s slung over their shoulders. She tapped the face of one of the men, in his late forties with two gold front teeth and a thick scar across his chin. ‘This is the uncle. He runs things out in Somalia but since Abshir was taken into custody Crazy Boy has been pulling the strings from here. The uncle’s name is Blue.’

‘Blue?’