He didn’t answer.

Eventually Kate forced herself from the chair and went to shower. She had to resist the temptation to look at her phone while she dressed, but when she could stave it off no longer, there was still no reply from Sergei.

The sense of anxiety, of dread, even, wrapped itself around her, but she forced herself through it, as if in a fog, and found herself the first at the breakfast buffet. She filled her plate and went to a remote corner table. She ordered coffee and drank it too fast. She didn’t feel like eating. She wondered how Fiona and Gus were getting on at home. She called Rose’s mobile, but got no reply there either.

Neither Julie nor Suzy made it to breakfast, so they met at eight forty-five in the lobby as agreed. Kate had her earpiece in and she set off on the route they had all arranged in advance with Danny.

She walked through the centre of the Tiergarten, skirting the Rose Garden, and then under the Brandenburg Gate to allow Danny and his team time to assess whether she was being watched and followed by members of any foreign intelligence service, most notably, of course, the Russians.

The idea was to move from crowded areas to open ones and back again, while officers on the streets worked behind her to get a sense of what they might or might not be up against. Danny, meanwhile, monitored the electronic activity in the immediate vicinity of her progress to check for any spikes that might suggest hostile officers communicating with each other while in pursuit.

Kate was halfway down Unter den Linden when the tiny microphone in her ear came to life with Danny’s calm, steady voice. ‘Take a turn into Bebelplatz.’

She did so, ambling slowly to the centre of the famous square, in which the Nazis had burnt books, to look through the glass window in the cobbles at its centre, which afforded a view of the library built in memorial beneath.

She returned to Unter den Linden and continued on past Museum Island to Alexanderplatz, which still had the bleak air of the square in east Berlin it had once been.

Despite her leisurely pace, Kate reached the corner of the square early and Danny instructed her to carry on beyond it. ‘Need a bit more to be sure,’ he said.

She walked on under the S-Bahn and swung left into Münzstrasse. Halfway down it, she turned into a vintage shop, where ‘The Eton Rifles’ by The Jam was playing on an old turntable. It was a pick-and-weigh store, where your choices were measured by the kilo, full of ripped jeans, denim shorts, leather belts, bags and jackets, sunglasses and every kind of hat that might have been fashionable in the sixties, seventies or eighties.

As she stepped back on to Münzstrasse, Danny’s voice rang in her ear: ‘Clear. Go back to the meet point.’

Kate retraced her steps, past the homeless people sleeping beneath the underpass, until she was standing by the bus stop in the corner of Alexanderplatz.