After she’d eaten, Kate washed her face again, feeling worse than she had, and put on some make-up. She glanced through a basic tourist guide she had procured from Reception, then set out just after ten, walking northwards into the drizzling rain.

Dry-cleaning – checking you were not being followed – was difficult, time-consuming and laborious on any day, but particularly so when operating alone and with a thumping hangover. Kate had chosen a simple, winding route through Josefov, the old Jewish Quarter, in an attempt to convince Suzy Spencer’s watchers – and anyone else who might be on her tail – that she was engaged in nothing more dramatic than some essential sightseeing in the few hours before heading to the airport.

Josefov, which is encircled by the river and the Old Town, was an enclosed ghetto in which the city’s Jews had once been confined, before being gradually cleared out in the nineteenth century. Those who were left were murdered during the terrible days of the Holocaust.

Kate started by the river at the St Agnes of Bohemia Convent, then circled to the corner of Bilkova and Elišky Krásnohorské, where a large apartment block with a few simple repeated geometrical shapes on a plain façade stood out from the flowing art-nouveau decoration of many of the surrounding buildings. She stood in front of this striking example of the cubist architecture that was briefly popular in Bohemia and Austria both before and after the First World War.

She took a picture on her phone and moved on to the Jewish Museum, then the Old Jewish Cemetery, with its crooked gravestones and Hebrew inscriptions.

She ambled past all the natural tourist sights of Josefov and made a point of moving through crowded areas, then more deserted backstreets, stopping frequently to take a picture or browse in a shop.

By the time she headed back towards the Old Town, she was puzzled by her conviction that neither Suzy Spencer’s team nor anyone else was watching her.

Which begged the question: why not? If she was a target yesterday, why was she not today?

She had intended to catch the tram to Vysehrad, thinning the pursuers by stringing out their resources and doubling back in a taxi, but she could no longer see the point. So, she was back in the Old Town Square early for her meetings and wiled away twenty minutes with a coffee while admiring the Rococo splendour of the Kinsky Palace.

She took in the occupants of the square in a steady, methodical way, sweeping from one side to the other and back again. If the Russians hadn’t been watching her already this morning – and she had to face the possibility that she was losing her touch – they certainly would be now.

At five to twelve, Stuart entered the square and she watched him for two or three minutes as he glanced nervously up at the astronomical clock, then at the tourists around him.

Why was he so on edge?