‘They worry me,’ said Frend.

‘They should, but we’ll take care of them. Consider it a goodwill gesture – or proof of our seriousness. Whichever makes you more comfortable.’

‘To be honest,’ said Frend, ‘neither does.’

‘To be honest,’ said Angel, ‘I don’t care.’

Angel and Louis met for dinner at China Kitchen No. 27 on Linke Wienzeile, in what passed for Vienna’s Chinatown. Both of them had eaten enough Austrian food for the time being, and Sichuan appealed. The spiciness was enough to make Angel sweat, which was always a good sign. They were one of only two Western couples in the restaurant, the other being a pair of young Scandinavian tourists who spent their time taking photos of their food and conversing in what sounded like Danish. The rest of the tables appeared to be occupied entirely by noisy Chinese family groups. It meant that Louis and Angel could converse without the Austrian police listening in, unless the force had a vast resource of elderly Chinese operatives or Instagram-obsessed Danes upon which to draw. Anyway, Angel thought that the police had largely lost interest in him for the present. Some of the detectives might have entertained doubts about aspects of his story, but not enough to justify trailing him around Vienna.

They ordered double-cooked pork belly and peppery Dan Dan noodles, and stuck to beer for the main courses, with green tea to follow. The pot of tea had just arrived at their table when Louis received a call with a Virginia area code. He stepped outside to take it.

‘We think that’s a throwaway phone Rafi is using,’ said Harris.

‘Duh,’ said Louis. ‘If that’s the kind of expertise my tax dollars are buying back home, I may have to relocate to North Korea.’

‘We also believe it’s been reserved solely for contact with you. It’s only been used once in the last five days, in Salzburg, and then for a call that wasn’t answered.’

‘A test.’

‘Most likely,’ said Harris.

Either Rafi was very confident of hearing from him, Louis thought, or that phone was just one of a bunch sitting on a table somewhere, plugged into a mass of power outlets, while bored men with beards took turns monitoring them for incoming calls. Some or all of those calls might not even be answered, but would be used solely to instigate a callback, in all likelihood from another location entirely.

‘So I use the number Rafi gave me, and you track the returned call?’ said Louis.